Researchers in China have made what they claim to be the first samples of pure hexagonal diamond, a theorized rare variant of superstrong diamond found in meteorites from shattered dwarf planets.

Natural diamond, also called cubic diamond, has been considered the hardest natural material on Earth for so long that the Mohs hardness scale, which rates minerals' resistance to scratching, uses diamond as the scale's upper limit. It's called cubic diamond for its neat arrangements of carbon atoms in a cubic structure. In contrast, hexagonal diamond organizes carbon atoms in a lattice made of hexagons, like a honeycomb.

An elusive mineral

In 1962, researchers at the Pittsburg Coal Research Center theorized that layers of carbon atoms making up diamond could be organized in a hexagonal lattice instead of a cubic one, thanks to how carbon forms bonds with other carbon atoms. In 1967, researchers discovered hexagonal diamond — or lonsdaleite — in the lab, suspecting it could be harder than cubic diamond.

They started looking for it in a special type of diamond-rich meteorite called ureilite, which forms from the mantle of smashed dwarf planets. The first detections of hexagonal diamond in the wild were documented in a 1967 paper; three Canyon Diablo meteorites (fragments of an asteroid that created a large crater in Arizona) with about 30% hexagonal and 70% cubic diamond phases, and Goalpara meteorites (found in Assam, India) that had a small amount of hexagonal diamond.

Not everyone agrees that the Canyon Diablo lonsdaleite exists. Some scientists thought the evidence could be explained by flawed cubic diamond that was stacked chaotically, and they weren't convinced that lonsdaleite had been detected in previous studies. However, multiple recent studies have identified lonsdaleite in meteorites and in lab samples, including a 2025 study that made small amounts of it in the lab.

The biggest challenge in identifying lonsdaleite is the lack of pure samples; in many cases, it is mixed with cubic diamond, graphite and other minerals. This makes it difficult ‪—‬ or even impossible ‪—‬ to test and measure its unique properties.

The new study, published March 4 in the journal Nature, addressed this problem by creating several pure hexagonal diamond samples about 0.06 inches (1.5 millimeters) in diameter ‪—‬ big enough to measure the samples' material properties. The team found that hexagonal diamond is both stiffer and harder than cubic diamond, and that it resists oxidation much more than cubic diamond does. This means hexagonal diamond can tolerate much higher temperatures without its surface getting all gunked up by reacting with oxygen, which is important for applications like drilling.

First evidence of hexagonal diamond?

The study also provides major evidence that hexagonal diamond is a real material. According to the study, "structural and spectroscopic analyses, supported by large-scale molecular dynamical simulations, unambiguously confirm the identity of HD (hexagonal diamond)."

To make the samples, the researchers compressed very organized graphite (graphite with carbon atoms neatly arranged) for 10 hours at 20 gigapascals, or about 200,000 times Earth's atmospheric pressure at sea level, and subjected them to temperatures ranging from 2,300 to 3,450 degrees Fahrenheit (1,300 to 1,900 degrees Celsius). At higher temperatures and pressures, the lonsdaleite started morphing into cubic diamond.

Hexagonal diamond could improve processes and tools that currently rely on cubic diamond, like drilling and cutting tools, polishing abrasive coatings, and dissipating heat from electronics. Its presence in meteorites can also tell us a lot about how the meteorite formed and where it came from, giving more clues about our solar system.

The elusive material "has potential applications in many fields, for example in cutting tools, in thermal management materials and in quantum sensing", Chong-Xin Shan, co-lead of the new Nature study and a physicist at Zhengzhou University, told Nature in an article.

The new study also provides "a practical strategy for producing HD (hexagonal diamond) in bulk form," opening the way for bigger samples, more scientific exploration, and industrial applications no longer limited by cubic diamond's hardness, according to the authors.

Television and internet ads regularly extol the classic beauty of gold jewelry and dazzling shine of cut gemstones. While we're all familiar with the precious gems — diamonds, sapphires, rubies and emeralds — there are hundreds more semiprecious gemstones, according to the International Gem Society. And sometimes even organic materials that are made into jewelry (like pearls) are considered gemstones.

Many gemstones are crafted into jewelry using gold, a soft, malleable element. Although gold is a relatively rare metal, scientists aren't sure exactly how much of it exists in the world — or how much is left to mine.

Think you're as brilliant as a multifaceted diamond? Start the quiz below, my ever-lovely jewels, to find out if you're stuck in an onyx night or if your sky is opalite.

Remember to log in to put your name on the leaderboard; hints are available if you click the yellow button!

You'll rock this!

Discover more science quizzes

• US volcano quiz: How many can you name in 10 minutes?
• What's inside Earth quiz: Test your knowledge of our planet's hidden layers
• US national parks quiz: How many of the 63 can you name?

A pair of diamonds that formed hundreds of kilometers deep in Earth's malleable mantle both contain specks of materials that form in completely opposing chemical environments — a combination so unusual that researchers thought their coexistence was "almost impossible." The substances' presence provides a window into the chemical goings-on of the mantle and the reactions that form diamonds.

The two diamond samples were found in a South African mine. As with plenty of other precious gemstones, they contain what are called inclusions — tiny bits of surrounding rocks captured as the diamonds form. These inclusions are loathed by most jewelers but are an exciting source of information for scientists. That's especially true when diamonds form deep in the unreachable mantle, because they carry these inclusions basically undisturbed to the surface — the only way those minerals can rise hundreds of kilometers without being altered from their original deep-mantle state.

The two new diamond samples each contain inclusions of carbonate minerals that are rich in oxygen atoms (a state known as oxidized) and oxygen-poor nickel alloys (a state known as reduced, in the parlance of chemistry). Much like how an acid and a base immediately react to form water and a salt, oxidized carbonate minerals and reduced metals don't coexist for long. Typically, diamond inclusions show just one or the other, so the presence of both perplexed Yaakov Weiss, a senior lecturer in Earth sciences at the Hebrew University of Jerusalem, and his colleagues — so much so that they initially put the samples aside for a year in confusion, he says.

But when they reanalyzed the diamonds, the researchers realized that the inclusions capture a snapshot of the reaction that made the sparkling stones and confirm for the first time that diamonds can form when carbonate minerals and reduced metals in the mantle react. The new samples are the first time scientists have ever seen the midpoint of that reaction captured in a natural diamond.

"It's basically two sides of the [oxidation] spectrum," says Weiss, the senior author of the new study describing the find, which was published on Monday in Nature Geoscience.

The find has implications for what lies in the mantle's mysterious middle. As you travel deeper into the earth, away from the surface, the rocks and minerals become increasingly reduced, with fewer and fewer oxygen molecules available, but there is little direct evidence of this shift from the mantle.

Theoretical calculations have given researchers a notion of how the planet shifts from oxidized to reduced with depth. "We knew about that reduction with some empirical data, with real samples down to maybe 200 kilometers," says Maya Kopylova, a professor of Earth, ocean and atmospheric science at the University of British Columbia, who was not involved in the new study but who wrote an editorial accompanying the paper. "What happened below 200 km [was] just our idea, our models, because it's so difficult to get the materials." There are only a few samples from below this depth, she said.

These new samples, which come from between 280 and 470 km below Earth's surface, provide the first real-world fact-check on this theoretical mantle chemistry. One finding, Weiss says, is that oxidized melted material exists deeper than expected. Kimberlites, the erupted rocks that bring diamonds to the surface, are oxidized, so researchers had thought they couldn't originate much below 300 km of depth. But these findings suggest that oxidized rocks occur deeper than that — and thus so might kimberlite rocks.

Diamond-forming reactions likely happen when carbonate fluids are dragged down by subducting tectonic plates, which bring oxygen-heavy minerals in contact with the metal alloys of the mantle, Weiss says. (Another way chemists think diamonds may form is by precipitating out of carbon-rich fluids that cool as they rise upward in the mantle, like sugar crystalizing from syrup. The new paper doesn't rule out that process happening as well.)

The nickel-rich inclusions might also help explain an odd occurrence in some diamonds: occasional atoms of nickel seem to replace the carbon of these diamonds' crystal lattice. That's been a mystery, Kopylova says, because nickel is so much heavier than carbon that it shouldn't be able to easily swap into the crystal structure. "Now, looking at these data, I see that it might be just a sign of diamond formation at certain depths," she says. "That would be very interesting to investigate further."

This article was first published at Scientific American. © ScientificAmerican.com. All rights reserved. Follow on TikTok and Instagram, X and Facebook.

Diamonds aren't always colorless; they can also be blue, yellow, green and even pink. But what makes these jewels come in varied hues?

At their base, diamonds are made of a single element: carbon. "It's just pure carbon," forged into treasure under very high pressures, said Luc Doucet, a senior research fellow of geology at Curtin University in Australia. They typically form deep beneath Earth's surface, more than 100 miles (161 kilometers) down in the planet’s mantle. Here, the pressure and temperature are extreme enough for the carbon atoms to bind together in a tight lattice.

After forming, diamonds need to rise to the surface very quickly for their lattice to stay intact. This usually happens when volcanic eruptions eject the rocks up from the depths. If a diamond stays in the deep, they may melt or transform into graphite over the course of millions of years.

"We're actually very lucky that we even get to find them, because they have to then be expelled from the deep Earth," said Gabriela Farfan, the Coralyn Whitney curator of gems and minerals at the Smithsonian National Museum of Natural History.

The majority of diamonds are colorless. But there are a couple of ways normal diamonds can turn into "fancy color diamonds," Farfan said.

First, like all minerals, diamonds can get impurities when they form. These flaws are elements other than carbon that get integrated to the gem's structure. But because carbon molecules are so small and very tightly packed, very few elements can get introduced into diamonds. "There aren't very many elements that can substitute in," Farfan said.

Related: Which are rarer: diamonds or emeralds?

However, there are a few exceptions. Nitrogen, carbon's neighbor on the periodic table, can sneak into the diamond's lattice, making yellow or orange diamonds. Boron, another element with a small atomic radius, can make striking blue diamonds, such as the famous Hope Diamond.

Radioactive radiation can also make diamonds green. This can happen if the neighboring rocks near the gems have uranium, which can "expel atoms to create vacancies" in the diamond's structure, Farfan said.

Diamonds can also get their color through structural deformities. This is how pink and red diamonds form. These stones get these hues because their carbon lattices become warped when they are deep inside the planet.

A diamond has to be squished in just the right way to take on a pinkish or bright-red hue. "It's kind of like Goldilocks," Doucet said. If a diamond is put under too much pressure, it can turn brown; if it's not under enough pressure, it stays colorless. "There are a lot of brown diamonds, and very, very few pink diamonds," Doucet noted.

Interestingly, because of how pink and red diamonds form, scientists can analyze these gems and understand exactly where and when in Earth's crust they originate. The geologic processes of an area leaves behind a signature in a diamond’s deformities. "So in this way, pink [and red] diamonds are the only ones you could potentially try and trace back to a geographic region," Farfan said.

For instance, Doucet studied pink diamonds from the Argyle mine in Western Australia, one of the largest diamond mines in the world. By looking at the gems' structure, he and his colleagues pinpointed that the stones were made during the breakup of Earth's first supercontinent 1.3 billion years ago. The results were published in a 2023 study in the journal Nature Communications.

Farfan pointed out that the Winston Diamond, which was recently put on display at the Smithsonian National Museum of Natural History, is bright red. And based on an analysis published in the journal Gems & Gemology, it likely came from somewhere in Venezuela or Brazil.

Studying these fancy color diamonds can also be a useful tool for science. They can help researchers understand what was going on inside Earth and how carbon cycles shifted throughout the planet's history, Doucet said.

These diamonds are special because "Earth produced them under such unique circumstances,” Farfan said. "It's just a miracle that it even exists in the first place."

Mercury may have a thick layer of diamonds hundreds of miles below its surface, a new study shows. The findings, published June 14 in the journal Nature Communications, may help solve mysteries about the planet's composition and peculiar magnetic field.

Mercury is filled with mysteries. For one, it has a magnetic field. Although it's much weaker than Earth's, the magnetism is unexpected because the planet is tiny and appears to be geologically inactive. Mercury also has unusually dark surface patches that NASA's Messenger mission identified as graphite, a form of carbon. 

That latter feature is what sparked the curiosity of Yanhao Lin, a staff scientist at the Center for High Pressure Science and Technology Advanced Research in Beijing and co-author of the study. Mercury's extremely high carbon content "made me realize that something special probably happened within its interior," he said in a statement.

Despite Mercury’s oddities, scientists suspect it probably formed the way other terrestrial planets did: from the cooling of a hot magma ocean. In Mercury's case, this ocean was likely rich in carbon and silicate. First, metals coagulated within it, forming a central core, while the remaining magma crystallized into the planet's middle mantle and outer crust. 

For years, researchers thought the mantle's temperature and pressure were just high enough for carbon to form graphite, which, being lighter than the mantle, floated to the surface. But a 2019 study suggested that Mercury's mantle may be 80 miles (50 kilometers) deeper than previously thought. That would considerably ramp up the pressure and temperature at the boundary between the core and the mantle, creating conditions where the carbon could crystallize into diamond. 

"We believe that diamond could have been formed by two processes," studyo co-author Olivier Namur, an associate professor at KU Leuven, told Live Science's sister site Space.com. "First is the crystallization of the magma ocean, but this process likely contributed to forming only a very thin diamond layer at the core/mantle interface. Secondly, and most importantly, the crystallization of the metal core of Mercury."

To investigate these possibilities, a team of Belgian and Chinese researchers, including Lin,  whipped up chemical soups that included iron, silica and carbon. Such mixtures, similar in composition to certain kinds of meteorites, are thought to mimic the infant Mercury's magma ocean. The researchers also swamped these soups with varying amounts of iron sulfide; they figured the magma ocean contained loads of sulfur, as Mercury's present-day surface is also sulfur-rich. 

Related: Uranus and Neptune aren't made of what we thought, new study hints

Using a multiple-anvil press, the team subjected the chemical mixtures to crushing pressures of 7 gigapascals — roughly 70,000 times the pressure of Earth's atmosphere at sea level — and temperatures of up to 3,578 degrees Fahrenheit (1,970 degrees Celsius). These extreme conditions simulate those deep within Mercury.

In addition, the researchers used computer models to get more precise measurements of the pressure and temperature at Mercury's core-mantle boundary, besides simulating the physical conditions under which graphite or diamond would be stable. Such computer models, according to Lin, tell us about the fundamental structures of a planet's interior. 

The experiments showed that minerals such as olivine likely formed in the mantle — a finding that was consistent with previous studies. However, the team also discovered that adding sulfur to the chemical brew caused it to solidify only at much higher temperatures. Such conditions are more favorable for forming diamonds. Indeed, the team's computer simulations showed that, under these revised conditions, diamonds may have crystallized when Mercury's inner core solidified. Because it was less dense than the core, it then floated up to the core-mantle boundary. The calculations also showed that the diamonds, if present, form a layer with an average thickness of about 9 miles (15 km).  

Mining these gems isn't exactly feasible, however. Apart from the planet's extreme temperatures, the diamonds are way too deep — about 300 miles (485 km) below  the surface — to be extracted. 

But the gemstones are important for a different reason: They may be responsible for Mercury's magnetic field. The diamonds may help transfer heat between the core and the mantle, which would create temperature differences and cause liquid iron to swirl, thereby creating a magnetic field, Lin explained. 

The results could also help to explain how carbon-rich exoplanets evolve. "The processes that led to the formation of a diamond layer on Mercury might also have occurred on other planets, potentially leaving similar signatures," Lin said. 

More clues may come from BepiColombo, a joint mission of the European Space Agency and the Japan Aerospace Exploration Agency. Launched in 2018, the spacecraft is scheduled to begin orbiting Mercury in 2025.   

Editor's note: This article was updated on Aug. 1, 2024 to include new quotes from the authors. The original article was published July 18.  

The Argyle mine held the biggest cache of pink diamonds ever discovered on Earth. Unlike blue and yellow diamonds, which are tinted by impurities like nitrogen and boron, pink diamonds get their color through geological processes that distort their crystalline structure. Pink diamonds are extremely rare and can fetch more than $2 million per carat (1 carat is equal to 0.2 grams, or 0.007 ounces), according to the International Gem Society.

The Argyle mine closed in 2020 due to a dwindling supply of diamonds and unfavorable economic conditions, including a rise in operational costs. The mine sits on the shores of Lake Argyle in a remote region of northeast Western Australia, 340 miles (550 kilometers) southeast of Darwin. Mining operations there lasted 37 years and yielded more than 865 million carats (191 tons, or 172 metric tons) of rough diamonds — including white, blue, violet, pink and red diamonds, according to Rio Tinto, the company that owned and operated the mine.

Related: Fountains of diamonds that erupt from Earth's center are revealing the lost history of supercontinents 

The Argyle rock formation is an unusual spot for diamonds, because it sits on the edge of a continent rather than in the middle, where the precious stones typically emerge. In addition, diamonds are usually found in kimberlite rock formations, but the Argyle formation features a type of volcanic rock called olivine lamproite.

Researchers dated the rocks at Argyle shortly after the site was discovered in 1979. Initial results pinned their age somewhere between 1.1 and 1.2 billion years old, but last year, a new study revealed the rocks are 1.3 billion years old. This puts the Argyle formation's origins right at the start of the breakup of the supercontinent Nuna, revealing clues about how the diamonds formed — and why so many of them are pink.

Pink diamonds are born out of specific heat and pressure conditions that arise when tectonic plates collide. The sheer force of these collisions can bend the crystal lattice of pre-existing diamonds in a way that colors them different shades of pink — although too much force can turn them brown, Hugo Olierook, a senior research fellow at Curtin University in Australia and lead author of the 2023 study, previously told Live Science. 

The supercontinent Nuna formed when two sections of Earth's crust crashed into each other around 1.8 billion years ago. The region in which they are thought to have smashed together overlaps with the present-day Argyle formation, suggesting the collision gave rise to Argyle's pink diamonds. At that point in time, however, the diamonds would have been buried deep within the crust.

But 500 million years later, when Nuna began to break apart as the tectonic plates moved away from one another, the rocks carrying the diamonds rose to Earth's surface. Those rocks also contained an abundance of brown diamonds, which Rio Tinto mined and sold in huge numbers.

Argyle is an exceptional spot, and while it's possible there might be another such cache of diamonds somewhere, finding it will "take a lot of luck," Olierook said.

Scientists have used a new technique to synthesize diamonds at normal, atmospheric pressure and without a starter gem, which could make the precious gemstones much easier to grow in the lab.     

Natural diamonds form in Earth's mantle, the molten zone buried hundreds of miles beneath the planet's surface. The process takes place under tremendous pressures of several gigapascals and scorching temperatures exceeding 2,700 degrees Fahrenheit (1,500 degrees Celsius).

Similar conditions are employed in the method currently used to synthesize 99% of all artificially created diamonds. Called high-pressure and high-temperature (HPHT) growth, this method uses these extreme settings to coax carbon dissolved in liquid metals, like iron, to convert it to diamond around a small seed, or starter diamond. 

However, the high pressures and temperatures are difficult to produce and maintain. Plus, the components involved affect the diamonds' size, with the largest being about a cubic centimeter, or about as big as a blueberry. Besides, HPHT takes a fairly long time — a week or two — to produce even these tiny gems. Another method, called chemical vapor deposition, eliminates some requirements of HPHT, like high pressures. But others persist, like the need for seeds.

The new technique eliminates some drawbacks of both synthesis processes. A team led by Rodney Ruoff, a physical chemist at the Institute for Basic Science in South Korea, published their findings April 24 in the journal Nature. 

Related: Scientists may have pinpointed the true origin of the Hope Diamond and other pristine gemstones

The diamond crucible

The novel method was a long time in the making. "For over a decade I have been thinking about new ways to grow diamonds, as I thought it might be possible to achieve this in what might be unexpected (per 'conventional' thinking) ways," Ruoff told Live Science by email.

To start out, the researchers used electrically heated gallium with a bit of silicon in a graphite crucible. Gallium may seem like an esoteric element, but it was selected because a previous, unrelated study showed that it could catalyze the formation of graphene from methane. Graphene, like diamond, is pure carbon, but it contains the atoms in one layer rather than in the gemstone's tetrahedral orientation. 

The researchers housed the crucible in a home-built chamber maintained at sea-level atmospheric pressure, through which superhot, carbon-rich methane gas could be flushed. Designed by co-author Won Kyung Seong, also of the Institute for Basic Science, this 2.4-gallon (9 liters) chamber could be readied for experimentation in just 15 minutes, allowing the team to rapidly undertake runs with different concentrations of metals and gases. 

Through such tweaking, the researchers figured that a gallium-nickel-iron mixture — coupled with a pinch of silicon — was optimal for catalyzing the growth of diamonds. Indeed, with this blend, the team obtained diamonds from the crucible's base after just 15 minutes. Within two and a half hours, a more complete diamond film formed. Spectroscopic analyses showed that this film was largely pure but contained a few silicon atoms.

The minutiae of the mechanism that formed the diamonds are still largely murky, but the researchers think a temperature drop drives carbon from the methane toward the crucible's center, where it coalesces into diamond. Plus, without silicon, no diamonds form, so the researchers think it may act as a seed for the carbon to crystallize around. 

However, the new method has its own challenges. One problem is that the diamonds grown with this technique are tiny; the largest ones are hundreds of thousands of times smaller than the ones grown with HPHT.  That makes them too small to be used as jewels.

Other potential uses — for example, in more technological applications like polishing and drilling — for the diamonds synthesized with the new technique are unclear. However, because the process involves low pressure, Ruoff said, it might significantly scale up diamond synthesis. 

"In about a year or two, the world might have a clearer picture of things like possible commercial impact," he added.  

Researchers may have found the true origin of the Hope Diamond, the Koh-i-noor and other famous, flawless gemstones. 

These diamonds, known collectively as the Golconda diamonds, are special because they have few inclusions and are very low in nitrogen, making them very clear and free of sparkle-disrupting flaws. They are also large. The Koh-i-noor, now one of the British Crown Jewels, weighs a whopping 105.60 carats. The Hope Diamond, held at the Smithsonian's National Museum of Natural History in Washington, D.C., weighs 45.52 carats. 

These diamonds were discovered in southern India between the 1600s and the 1800s and carry stories of colonialism and controversy. Most are now held outside India, and there are calls to repatriate many of them because of their cultural and religious significance. These diamonds also tend to have a larger-than-life aura. The Hope Diamond, for example, is said to be cursed. So is the Regent Diamond, now in the collection at the Louvre. (That diamond is also said to have been smuggled out of a mine by an enslaved miner who stashed it in an open leg wound.)

The Golconda diamonds were found in so-called placer mines, which are shallow pits dug into riverside sediments; the diamonds were carried with these sediments to the riverbanks. But diamonds come to Earth's surface inside large volcanic eruptions called kimberlites, and no one knew where the kimberlite rocks that bore these diamonds might be found.  

Now, new research published March 15 in the Journal of Earth System Science suggests that the diamonds may have come from the Wajrakarur kimberlite field in modern-day Andhra Pradesh, up to 186 miles (300 kilometers) from where they were mined. 

The findings do leave some uncertainty, however, said Yaakov Weiss, a geochemist who studies diamonds at The Hebrew University of Jerusalem. The researchers studied the geochemistry of common diamonds from the lithosphere — the rigid crust and upper mantle — and determined that the Wajrakarur field could host diamonds. The Golconda diamonds, however, form deeper in the mantle, perhaps as deep as the transition zone near Earth's core. 

"The analysis is related mainly to lithospheric diamonds, and we believe the larger diamonds are coming from deeper in the Earth," Weiss, who was not involved in the research but reviewed the paper for publication, told Live Science. "So it still has some uncertainty." 

To attempt to trace the source of the Golconda diamonds, Hero Kalra, Ashish Dongre and Swapnil Vyas — all geoscientists at Savitribai Phule Pune University in India — studied the chemical signatures of nearby kimberlites and lamproites. These are rocks that came from the base of the crust and upper mantle, where most diamonds form. 

They found that kimberlite rocks from the Wajrakarur field likely rose from the depths where diamonds are forged and host minerals that tend to co-occur with diamonds. They then conducted surveys using remote-sensing data, such as satellite imagery and vegetation and moisture measurements. 

These surveys revealed a long-dry ancient river channel that could have swept diamonds from Wajrakarur to the Krishna River and its tributaries, where the stones were eventually found. 

Linking a kimberlite field where standard lithospheric diamonds are found with the deeper Golconda diamonds isn't a slam dunk, though, Weiss warned. These deeper diamonds have different chemistries and could, theoretically, still have come from elsewhere. 

No one knows exactly how these deep diamonds reach Earth's surface, he said. They may rise up from the deep mantle on hot fountains of magma known as mantle plumes and then get wedged in the lower crust and upper mantle with more run-of-the-mill diamonds that form in those regions. Then, when a kimberlite eruption occurs (probably as a result of a supercontinent breakup), all of the diamonds erupt to the surface at once. 

However, it's very challenging to discover the origins of the Golconda diamonds directly, because these diamonds lack the tiny inclusions that hold fluids from the mantle where the diamonds first formed. This makes them beautiful and sought-after as gems, Weiss said, but it gives geochemists very little to work with. As a result, the Golconda diamonds will probably always retain a bit of mystery. 

Researchers in Japan have created the first "n-channel" diamond-based transistor, inching us closer to processors that can operate at super-high temperatures. This eliminates the need for direct cooling and increases the range of environments where processors can operate.

By using diamond in a transistor — electrical switches that flip between 1 and 0 when voltage is applied — the research opens up the prospect of electronics that are smaller, faster and more power-efficient. 

They can also work in much harsher environments than conventional components — operating in temperatures above 572 degrees Fahrenheit (300 degrees Celsius) rather than the typical transistor's limit of 212 degrees Fahrenheit (100 degrees Celsius) — and can endure much higher voltages before breaking down. 

The scientists detailed their findings in a paper published Jan. 19 in the journal Advanced Science. 

Silicon transistors have been used to make processors since the early 1960s, but it's reaching its physical limitations as the size of the manufacturing process (as low as 3 nanometers) approaches the 0.2-nanometer width of silicon atoms. 

There are several different types of transistors out there, but the most commonly used is metal-oxide-semiconductor field-effect transistor (MOSFET), with "metal-oxide-semiconductor" referring to the silicon wafer of a conventional computer chip. 

Within MOSFETs, there are different configurations too — referred to as n-channel and p-channel. N-channel transistors use electrons to carry charge while p-channel transistors use "holes" — that is, in greatly simplified terms, the gaps left behind by escaped electrons. N-channel transistors are commonly found in high-side power switches to protect batteries. 

Related: Universal memory' breakthrough brings the next generation of computers 1 step closer to major speed boost

In the new study, the researchers built a transistor with two "phosphorus-doped diamond epilayers." Phosphorus doping, which simply means adding the element to the layers, is necessary to add conductivity.  This is the n-channel layer, which carries free electrons and would replace the silicon-based layer in a conventional chip. When enough electrons flow, they connect two ends of a gate — known as "the source" and "the drain." This closes the circuit to represent a 1 rather than a 0.

The team lightly doped the negative layer with phosphorus and heavily doped the second, positive layer. The scientists then formed annealed titanium "source" and "drain" contacts on the top, heavily doped layer, before adding 30-nanometer-thick aluminum trioxide to serve as an insulator. The result was the world’s first working n-channel MOSFET transistor made using diamond.

The researchers then put the transistor through a series of tests to check for conductivity performance. "The n-type diamond MOSFETs exhibit a high field-effect mobility around 150cm2/V/sec at 573K," they said in their paper, referring to high conductivity and stability at extremely high temperatures. This was "the highest among all the n-channel MOSFETs based on wide-bandgap semiconductors," they noted.

A bandgap, measured in electronvolts (a unit of kinetic energy) is an area within the n-channel in which valence electrons (those in an atom's outermost shell) can move freely. A wider bandgap means a component can operate at higher voltages and frequencies. Diamond has a 5.47eV bandgap compared with 1.12eV for silicon.

This is not the first diamond transistor breakthrough. Another team published a study in January 2022 in the journal Nature detailing how to create diamond-based p-channel wide-bandgap transistors. Until now, scientists have been unable to demonstrate a working n-channel diamond-based transistor.

When it comes to future applications for their transistor, the scientists suggested it could work in energy-efficient electronics, as well as spintronic devices and sensors made from micro-electromechanical systems (MEMS) that can operate in harsh environments, such as space. 

There are other uses for diamond semiconductors, including in supercomputers,  electric vehicles (EVs) as well as lighter and more durable consumer electronics.

Scientists have simulated an elusive, superstrong form of carbon that may be tougher than diamonds, the hardest known material. But observing the real thing might require a trip far outside our solar system, to the center of an exoplanet — a feat that's not likely anytime soon, or possibly ever.

BC8, as the superstrong carbon is known, is an eight-atom crystal that would be 30% more resistant to compression than diamonds, according to a new study. Scientists have been trying to synthesize this crystal in the lab, without success. The new simulation reveals that the material can be made only in a narrow range of pressures and temperatures, which might make that synthesis possible in the future, researchers reported in the study, which was published in The Journal of Physical Chemistry Letters in January.

The research also helps to reveal what might be at the hearts of carbon-rich exoplanets, which are predicted to have just the right conditions for the formation of BC8.

Related: 'Mind-boggling' alloy is Earth's toughest material, even at extreme temperatures

"[T]he extreme conditions prevailing within these carbon-rich exoplanets may give rise to structural forms of carbon such as diamond and BC8," study senior author Ivan Oleynik, a physics professor at the University of South Florida, said in a statement. "Therefore, an in-depth understanding of the properties of the BC8 carbon phase becomes critical for the development of accurate interior models of these exoplanets."

In the new research, Oleynik and his colleagues used Frontier, a supercomputer at the Oak Ridge Leadership Computing Facility in Tennessee. They ran simulations of billions of carbon atoms under different pressures and temperatures to understand how these amply available atoms can transform into a material so rare, it's never been observed.

They found that BC8 is likely very stable at very high pressures of 1,250 gigapascals and above. That's well over 12 million times the pressure of the atmosphere on Earth's surface. Theory also suggests, however, that the crystal, once formed, would remain stable at ambient temperatures. BC8's atomic structure is similar to a diamond's, but it lacks diamonds' cleavage planes, the gemstones' weakest points, study co-author Jon Eggert, a scientist at Lawrence Livermore National Laboratory (LLNL), said in a statement.

Armed with their new knowledge of BC8's formation pathways and stability, the researchers are making new attempts to synthesize the material at LLNL's National Ignition Facility. These types of methods involve shocking diamonds twice at upward of 45,000 mph (72,000 km/h) and then compressing them under enormous pressures.

In the twilight of the Cretaceous, 86 million years ago, a volcanic fissure in what is now South Africa rumbled to life. Below the surface, magma from hundreds of miles down shot upward as fast as a car on the autobahn — if that car were barreling through solid rock — chewing up rocks and minerals and carrying them toward the surface in a reverse avalanche.

What this looked like on the surface is lost to history, but it may have been as dramatic as the eruption of Mount Vesuvius. What it left behind was a series of carrot-shaped, igneous-rock-filled tubes under low, weathered white hills.

In 1869, a shepherd's discovery of a huge, sparkly rock on a nearby riverbank would catapult this unassuming landscape into infamy. The rock was an enormous diamond that would eventually be known as the Star of Africa, and the white hills hid what would become the Kimberley Mine, the epicenter of South Africa's diamond rush and quite possibly the largest hole on Earth ever dug out by hand.

Thanks to the Kimberley Mine, often called "The Big Hole," the formations where diamonds are found are now known as kimberlites. The formations are sprinkled across the globe, from Ukraine to Siberia to Western Australia, but they're relatively small and rare. What makes them special is that their magmas come from very deep down. There are still questions about precisely how deep, but they are known to arise from beneath the bases of continents at the border of the hot, convecting mantle. Some may originate even deeper, at the transition between the upper and lower mantle.

Related: What's inside Earth?

As such, these magmas tap into very deep, very ancient rock, and they interact with other processes that occur only in the deep Earth — namely, the formation of diamonds. To crystallize plain-old carbon into hard, sparkly diamond requires great pressure, so these gems form at least 93 miles (150 kilometers) down, in the deepest layers of the lithosphere, the scientific term for the crust and relatively rigid upper mantle. Some, known as sub-lithospheric diamonds, form even deeper, down to around 435 miles (700 km). Kimberlites, on their eruptive journeys to the surface, catch diamonds and drag them into the upper crust, delivering them relatively unscathed and sometimes even containing pockets of fluid from the mantle itself.

Researchers have long known that as tectonic plates grind under one another, they drag down carbon from the surface to depths where it can crystallize into diamond. Now, they're starting to see that what goes down must (sometimes) come up, and that this reappearance of carbon — now pressed into glittering gems — is also tied to the movements of tectonic plates. In particular, diamonds seem to erupt when supercontinents break apart.

"While these are different processes, together the diamonds and kimberlite can inform us about the life cycle of supercontinent times," said Suzette Timmerman, a geologist at the University of Bern in Switzerland who studies diamonds.

Coming to the surface

No one has ever seen a kimberlite eruption firsthand. There have been very few in the past 50 million years, and the most recent possible eruption, in the Igwisi Hills of Tanzania, occurred over 10,000 years ago. Not only that, but the main material in kimberlite, the mineral olivine, weathers away quickly on the surface, said Hugo Olierook, a research fellow at Curtin University in Australia.

This makes studying kimberlites challenging. Scientists are perplexed, for example, about the chemistry of the original source of the melted rock in the mantle, as well as about how kimberlites manage to punch through the stable cores of what geoscientists call "cratons" — the thick interior parts of continents that usually resist disruption.

A handful of recent studies are sketching out a new explanation for why this happens. The first clue is timing. It's long been noted that pulses of kimberlite activity seem to correspond with the approximate timing of supercontinent break-ups, said Kelly Russell, a volcanologist at the University of British Columbia in Canada. A 2018 study led by Sebastian Tappe, a geoscientist at The Arctic University of Norway, took a global look at this coincidence of timing and found that it up: There was a spike in kimberlite eruptions around the breakup of the supercontinent Nuna some 1.2 billion years ago to 1 billion years ago.

Another pulse occurred between 600 million and 500 million years ago, coinciding with the breakup of the supercontinent Rodinia, according to the 2018 research, followed by a smaller pulse between 400 million and 350 million years ago. But the most prolific period, accounting for 62.5% of all known kimberlites, occurred between 250 million and 50 million years ago. That range happens to coincide with the breakup of the supercontinent Pangaea. To some researchers, this suggests that supercontinent cycles are crucial for kimberlite eruptions.

"The breakup of these continents are fundamental to getting these diamonds up from these deep depths," Olierook told Live Science.

Olierook and his team recently analyzed the ages of unusual pink diamonds from a formation in western Australia and found they likely came to the surface about 1.3 billion years ago, within the window of Nuna breaking up. The new discovery links diamonds to the stretching of continental crust, Olierook said.

"It's those extensional forces that allow those little pockets of deep-seated magma to rise to the top," he said.

The march of the kimberlites

The tricky question, though, is how this happens. To get a kimberlite, there are two key ingredients: deep, melted rock rich in fluids, and a continental disruption that may bring that melt to the surface. No one knows what causes the formation of the kimberlite melt, but the chemistry of kimberlites is very different from that of the mantle rock it melts from. Kimberlites are also rich in volatiles such as water and carbon dioxide, which is what makes them so buoyant and high-velocity. They shoot through the crust like Champagne rushing through an uncorked bottle, ascending at up to 83 mph (134 km/h). For comparison, the magmas that flow out of the volcanoes in places like Hawaii max out at around 13.5 mph (21.7 km/h).

An August 2023 study used computer modeling to figure out how kimberlites can burst through the thick hearts of continents. The researchers found that the process of rifting, in which continental crust pulls apart, was key. The stretching creates peaks and valleys at both the surface and base of the continent. At the base, these jagged edges allow warm mantle materials to rise, and then cool and fall, creating eddies. These eddies mix materials from the base of the continents, making the frothy, buoyant kimberlites, which can then shoot up toward the surface, carrying any diamonds they might happen to run into on their way up.

This process began right where the continent was rifting apart, but modeling showed that these jagged regions of eddy formation destabilized neighboring areas on the craton, creating the same dynamics closer and closer to the continental interior. The result was a pattern of kimberlite eruptions starting near the rift zone but gradually marching into areas of stable crust. This slow march explains why kimberlite pulses don't peak until a bit after a big breakup begins, said Thomas Gernon, a geologist at the University of Southampton in the U.K. who led the study.

"You will see these peaks of kimberlites seem to happen after big supercontinents have broken up," he said. "But it's not just a one-hit thing; it's something that may last quite a long time after supercontinent breakups."

Kimberlites may be quite common at the bases of continents, said Tappe, whose 2018 study on kimberlites and supercontinent breakups came to similar conclusions as Gernon's. Tappe and his team found that these melts may have been particularly prominent during the breakup of Pangaea, because the mantle, which has been slowly cooling since Earth solidified, reached just the right temperature around 250 million years ago to have kimberlite-type melts dominate. Prior to that period, the rocks in that region may have been too hot to get that combination of melt and volatile material that makes kimberlites so eruptive. This may be one reason why most kimberlite diamond mines date from the breakup of Pangaea.

Messages in a diamond

As the dull, white hills that once covered the Kimberley Mine attest, kimberlites themselves can't say much about the mantle where they originated. They weather away within a few years, losing much of what makes them interesting on a chemical level. However, the diamonds carried within kimberlites are a different story. They have their own formation histories that don't coincide with the formation of the kimberlite magma itself. But their chance meetings hundreds of miles below the surface mean that bits of the mantle that would never otherwise see daylight can reach human hands.

These bits are microscopic pockets of fluid from the time the diamonds formed. Many of these "inclusions" date back hundreds of millions of years, while a few specimens count their ages in the billions. Plus, some of these diamonds form very deep in the mantle, so certain stones can carry materials from as far down as the boundary between the mantle and the core.

"Only in kimberlites we can see samples coming from 400 kilometers [250 miles], even down to 2,000 kilometers [1,200 miles]," said Maya Kopylova, a professor of diamond exploration at the University of British Columbia. "No other magmas on Earth do that."

Related: What's the deepest-forming gemstone on Earth?

While the eruption of diamonds can trace a story of supercontinent breakup, their formation may also provide a clue to how continents come together. In a study published in October 2023 in the journal Nature, Timmerman studied diamonds from Brazil and Guinea that formed between 186 and 434 miles deep (300 to 700 km). By dating fluid inclusions within the diamonds, Timmerman and her colleagues estimated that the diamonds formed around 650 million years ago, when the supercontinent Gondwana was forming. The diamonds probably stuck to the base of the continent and sat there for millennia until Gondwana broke up during the Cretaceous period and kimberlites brought them to surface, Timmerman told Live Science.

What was important about these superdeep diamonds, Timmerman said, was that they helped explain how continents grow. Supercontinents are built when oceanic crust pushes under continental crust. This process, called subduction, tugs two continents on opposite sides of an ocean closer together. This same subduction brings carbon to the depths, where it can be compressed into diamond.

Down in the mantle, bits of these subducting plates can become buoyant and rise back up, carrying superdeep diamonds with them, Timmerman explained. This material may stick to the bases of continents for millennia, helping them grow from below. It may also explain how superdeep diamonds land in a place where a kimberlite can catch them.

"Deep diamonds can inform us more about subduction processes, mantle convection, liquid-rock interactions and other processes happening below the crust during supercontinent cycles," Timmerman said.

There are many other questions to answer, she added. For instance, scientists still don't know how subducted plates change the bases of supercontinents and whether that affects how long a supercontinent lasts before breaking up. Another open question is whether this recycled crustal material influences when and where kimberlite magmas form.

Ancient diamonds may also tell us about other milestones in Earth's chaotic history.

Some diamonds are forged from carbon that was incorporated into Earth upon its formation, Olierook said, while others form from carbon from ancient life, dragged down along with slabs of subducted crust. It's possible to tell which process formed the diamonds by analyzing the molecular structure of the carbon within diamond inclusions. These inclusions can thus hold secrets about hazy numbers in Earth history, such as when widespread subduction began or when life in the oceans became prevalent.

But to get at those answers, researchers will need to get better at figuring out how old diamonds are. And they'll need more diamonds that are both ancient and from the deepest depths.

"Going back in time from the most recent supercontinent breakup to the ones before that," Olierook said, "I strongly suspect there are still lots to be discovered."

This year was all about White Gladis, the orca that became a global sensation because of her apparent hatred for boats. The orcas began ramming boats in 2020, but it wasn't clear what had kicked off this weird behavior — researchers were understandably hesitant to unpick the thoughts of a pod of killer whales.

But in May, scientists identified White Gladis as the ringleader and finally explained her motivations. Experts said a traumatic experience with a boat had flipped a switch. She started attacking boats. Others then copied her behavior and the boat-sinking saga began.

Seeing a real-time shift among a population of super-smart predators has been fascinating — and understanding that the boats and their human owners started it should make us think a little more about how we interact with our environment. The orcas were in the oceans first.

Scientists don't know what'll happen next. They're social animals and terrifying behaviors can spread among pods. Or they may just get bored of the boats and stop. We'll learn more next year.

Orcas have sunk 3 boats in Europe and appear to be teaching others to do the same. But why?

Imagine diamonds exploding from Earth in huge volcanic eruptions akin to Mount Vesuvius. That's what scientists think happened when the supercontinent Pangaea broke up — the centers of these mammoth landmasses become so stretched and thin, diamonds that have been patiently sitting beneath them come shooting up from Earth's core in a big old sparkly explosion. And Live Science will take a deeper look at what these sparkly gems can reveal about the birth and death of supercontinents in 2024, so stay tuned.

Fountains of diamonds erupt from Earth's center as supercontinents break up

A dolphin with thumbs was spotted playing in the Gulf of Corinth. What a wonderful world we live in.

See photos of the extremely rare dolphin with thumbs

Thanks for reading, looking forward to 2024!
Happy New Year!

Diamonds are prized for their hardness. In jewelry, they can last generations and resist scratches during day-to-day wear. As blades or drill bits, they can penetrate almost anything without getting destroyed. As a powder, diamonds polish up gemstones, metals and other materials.

So is anything harder than diamond? It turns out, figuring out the answer is, well, a bit hard.

For most practical purposes, diamond is still the hardest material, said Richard Kaner, a materials chemist at the University of California, Los Angeles. There are ways to create diamonds that are harder than standard gem diamonds. And there are other materials that might theoretically be harder than diamond, but they don't exist in a form that you could hold in your hand or use widely.

Related: Which is rarer: Gold or diamonds?

While anyone wearing a diamond ring can attest to the crystal's durability, it's important to understand that "hardness" means something very specific to scientists, said Paul Asimow, a geochemist at Caltech. It's often confused with other qualities, like stiffness or strength. These factors sometimes, but not always, correlate with hardness.

Diamond, for example, is very hard but only moderately stiff. And it's surprisingly easy to break: It shatters easily along its crystal faces, which is how gem cutters can create beautiful, multifaceted diamonds that sparkle.

Scientists measure hardness in a few different ways. Geologists often rely on a comparative metric called the Mohs hardness scale, a way to identify minerals in the field based on whether they can scratch each other. Diamond is a 10 — the top of the scale — meaning it can scratch almost anything. Soft, crumbly talc is 1.

In the lab, materials scientists rely on a more precise measurement called the Vickers hardness test, which determines the hardness of a material based on the force required to indent it with a pointy tip. (To visualize this, imagine driving a pencil into a rubber eraser.)

Diamond is made up of carbon atoms arranged in a cubic lattice, held together by short, strong chemical bonds. This structure gives it its famous hardness. Most materials that claim to be harder than diamond come from slightly changing the classic diamond crystal structure, or swapping out some of the carbon atoms with atoms such as boron or nitrogen.

A prime contender for a material harder than diamond is lonsdaleite. Like diamond, lonsdaleite is made up of carbon atoms, but they are arranged into a hexagonal crystal structure instead of a cubic one.

"Lonsdaleite is very puzzling," Asimow told Live Science. Until recently, it had been found in such tiny quantities, mostly inside meteorites, that it wasn't clear whether it counted as a stand-alone material or if it was just a defect in the standard diamond crystal structure.

Recently, a team of scientists found micron-size lonsdaleite crystals in meteorites — still tiny, but much bigger crystals than previous finds. That's given the mineral more credibility, Asimow said. Other scientists have reported making lonsdaleite in the lab, though the crystals existed for only a fraction of a second.

So lonsdaleite is intriguing, but it won't be replacing diamond for applications like cutting, drilling or polishing anytime soon.

Playing with diamond's nanoscale structure can also make a material that's harder than a regular diamond. A material that's made up of many tiny diamond crystals will be harder than a gem-quality diamond that's a single crystal, because the nanoscale grains lock up instead of moving past one another. "Nanotwinned" diamonds, in which the grains form mirror-image patterns of each other, are reportedly double the hardness of regular diamonds.

At the end of the day, though, most scientists aren't pursuing superhard materials solely to set records — they're trying to create something useful.

"Materials scientists spend a lot of time inventing superhard materials that can be made at scale," Asimow said. "And for many purposes, being harder than diamond is not the design criteria." Scientists might want something almost as hard as diamond, but cheaper or easier to make in the lab.

For example, Kaner's lab has created a variety of superhard metals that could be used in industrial applications in place of diamond. One that's now available commercially is a  combination of tungsten and boron, with a few other metals sprinkled in. The shape of the crystals gives the material different properties in different directions — so, when held in the right orientation, it can scratch a diamond, Kaner told Live Science. It's also more affordable to create, in part because it doesn't require the high pressure conditions used to make diamonds in the lab, he noted.

So while diamond in its many forms still rules the roost in terms of hardness, the classic material might face other challenges to its throne going forward.

Earth may owe its supply of pink diamonds to the breakup of the planet's first supercontinent.

The Argyle formation in western Australia is the source of 90% of pink diamonds on Earth. It's an odd spot for diamonds: at the edge of a continent rather than in the center, where most diamond mines tend to be, and in a type of rock that is slightly different from the rock that usually bears diamonds.

Now, new research suggests that the strange color and strange geology likely come from a similar origin, the plate tectonics of the planet some 1.3 billion years ago. Recent studies from other researchers suggest that these large-scale continental movements are important for bringing diamonds of other colors to the surface, as well.

"The breakup of these continents are fundamental at getting these diamonds up from these deep depths," said Hugo Olierook, a research fellow at Curtin University in Australia and lead author of the new study on the origin of the pink diamonds, published today (Sept. 19) in the journal Nature Communications.

Pink diamonds are different from blue or yellow diamonds, which get their color from impurities like nitrogen and boron. In contrast, pink diamonds are colorful only because their crystalline structure has been bent. The Argyle also hosts a lot of brown diamonds, which get their color from an even greater deformation of the crystal structure.

"Pinks are, say, a small push, if you like," Olierook told Live Science."You push a little bit too hard and they turn brown."

Related: How do scientists figure out how old things are?

The Argyle diamond mine closed in 2020. Research from the 1980s, shortly after the discovery of the cache, had pegged the age of the rocks there at about 1.2 billion years. But even the scientists who did that original work were not convinced of that number, Olierook said, due to technical limitations. He and his colleagues decided to check again using modern equipment, particularly laser ablation technology that allowed them to carefully pinpoint the individual crystals in the rock they were dating.

These new results revealed that the pink-diamond-bearing Argyle is 100 million years older than previously believed, at 1.3 billion years in age. That puts its origin right at the beginning of the breakup of the supercontinent Nuna.

This paints a new picture of how the Argyle's pink diamonds came to be, Olierook said. First, some time around 1.8 billion years ago, two bits of continental crust smashed together as part of the formation of Nuna. What would eventually become the Argyle formation sat right at this juncture. The collision of the crust is probably what bent the diamonds and made them pink, Olierook said.

It was the breakup of Nuna, 500 million years later, that then brought the diamonds to the surface. The continent did not split right at the Argyle, but the stretching that went on likely weakened the "old wound" of the continental collision where the formation sits. This weakening allowed an eruption of deep rock — carrying those rare pink diamonds — that occurred over days to weeks.

"I think we’re seeing how in general, the mantle is destabilized when supercontinents break up," Olierook said. "That rifting process seems to not just work the edges, but also seems to work in the middle of continents, and that's perhaps what is allowing diamonds to come up in the middle of them" in most cases, he said.

Tracking diamonds' paths from the depths to the surface is helpful for understanding how carbon moves in and out of the planet's interior, Olierook said. (Diamonds are mostly pure carbon.) The Argyle is a pretty unique spot, he said, but there is a chance that pink diamonds could be found elsewhere on Earth.The problem is that if pink diamonds form on the edges of continents, they're likely to be buried under a lot of eroded-away rock and sediment, he said.

"I do think we will find another Argyle, another pink diamond treasure trove," he said, "but it’s going to take a lot of luck."

Editor's Note: This story was updated to correct the journal name. The research was published in Nature Communications, not Nature.

The breakup of supercontinents may trigger explosive eruptions that send fountains of diamonds shooting up to Earth's surface.

Diamonds form deep in Earth's crust, approximately 93 miles (150 kilometers) down. They are brought up to the surface very quickly in eruptions called kimberlites. These kimberlites travel at between 11 and 83 mph (18 to 133 km/h), and some eruptions may have created Mount Vesuvius-like explosions of gases and dust, said Thomas Gernon, a professor of Earth and climate science at the University of Southampton in England.

Researchers noticed that kimberlites occur most often during times when the tectonic plates are rearranging themselves in big ways, Gernon said, such as during the breakup of the supercontinent Pangaea. Oddly, though, kimberlites often erupt in the middle of continents, not at the edges of breakups — and this interior crust is thick, tough and hard to disrupt.

"The diamonds have been sat at the base of the continents for hundreds of millions or even billions of years," Gernon said. "There must be some stimulus that just drives them suddenly, because these eruptions themselves are really powerful, really explosive."

Gernon and his colleagues began by looking for correlations between the ages of kimberlites and the degree of plate fragmentation occurring at those times. They found that over the last 500 million years, there is a pattern where the plates start to pull apart, then 22 million to 30 million years later, kimberlite eruptions peak. (This pattern held over the last 1 billion years as well but with more uncertainty given the difficulties of tracing geologic cycles that far back.)

For example, the researchers found that kimberlite eruptions picked up in what is now Africa and South America starting about 25 million years after the breakup of the southern supercontinent Gondwana, about 180 million years ago. Today's North America also saw a spike in kimberlites after Pangaea began to rift apart around 250 million years ago. Interestingly, these kimberlite eruptions seemed to start at the edges of the rifts and then marched steadily toward the center of the land masses.

To figure out what was driving these patterns, the researchers used multiple computer models of the deep crust and upper mantle. They found that when tectonic plates pull apart, the base of the continental crust thins — just as the crust up top stretches out and forms valleys. Hot rock rises, comes into contact with this now-disrupted boundary, cools and sinks again, creating local areas of circulation.

These unstable regions can trigger instability in neighboring regions, gradually migrating thousands of miles toward the center of the continent. This finding matches the real-life pattern seen with kimberlite eruptions starting near rift zones and then moving to continental interiors, the researchers reported July 26 in the journal Nature.

But how do these instabilities cause explosive eruptions from deep in the crust? It's all in the mixing of just the right materials, Gernon said. The instabilities are enough to allow rock from the upper mantle and lower crust to flow against each other.

This churns together rock with lots of water and carbon dioxide trapped within it, along with many key kimberlite minerals — including diamonds. The result is like shaking a bottle of champagne, Gernon said: eruptions with a lot of explosive potential and buoyancy to drive them to the surface.

The findings could be useful in searching for undiscovered diamond deposits, Gernon said. They might also help explain why there are other types of volcanic eruptions that sometimes occur long after a supercontinent breakup in regions that should be largely stable.

"It’s a fundamental and highly organized physical process," Gernon said, "so it’s likely not just kimberlites responding to it, but it could be a whole array of Earth system processes that are responding to this as well."

Electricity keeps the lights on, powers electric vehicles, and even infuses our language — after all, attraction is often described as "feeling a spark." But how much do you know about what drives this physical phenomenon? 

We're cutting through the myths and misconceptions around electricity with these 10 shocking facts.

1. Reports about the discovery of electricity have been greatly exaggerated

Delve into the history of electricity and you'll find conflicting reports about its discovery. Was the original pioneer of electricity Benjamin Franklin, flying a key attached to a kite in a thunderstorm in the 1750s? Or was it Thales of Miletus, a Greek philosopher who supposedly experimented with amber and feathers in 600 B.C. to discover static electricity for the first time? 

Related: Who invented the lightbulb?

It was neither, really. Many uncited sources credit Thales of Miletus with discovering static, but a 2012 investigation published in the Journal of Electrostatics found that he never actually claimed to have discovered that amber, when rubbed, would attract light objects like feathers; rather, he mentioned static to bolster his argument that even inanimate objects might have a soul. And Ben Franklin's alleged kite experiment occurred well after scientists had already figured out that electricity existed. Franklin did propose the kite experiment as a way to discover if lightning was actually electrical discharge, but historians aren't certain whether he ever conducted the experiment himself, as there are only two sources that mention the experiment, and one was written some 15 years after the fact, according to the U.S. National Archives and Records Administration.

In reality, a lot of different people figured out electricity over centuries, in a lot of different ways. English physician William Gilbert experimented with magnets and electricity in the late 1500s and early 1600s, according to the BBC, and he coined the term "electricus" in 1600 to describe electric charges. The 17th-century English scientist and mythbuster Thomas Browne, who put a number of urban myths to the test in his book "Vulgar Errors," coined the term "electricity" before his death in 1682. Ben Franklin and his contemporaries were on the case in the 1700s, and by 1800, Italian inventor Alessandro Volta had figured out how to actually generate electricity by making primitive batteries out of zinc, copper, and saltwater-soaked cardboard. In 1831, English scientist Michael Faraday discovered a way to generate an electrical current by turning a magnet within a coil of wire. In other words, it was a group effort. 

Related: What is Faraday’s law of induction?

2. Electricity is just moving electrons 

Electricity is now so ubiquitous that it can be easy to forget the forces that make it possible. So why does electricity exist? The answer has to do with subatomic particles. 

The atoms that make up the matter in the universe each consist of a nucleus orbited by a cloud of negatively charged electrons. Some of these electrons are bound very tightly to their atom's nucleus, while others are more like free agents. When a force is applied, these electrons can move, according to the U.S. Energy Information Administration. Those moving electrons are electricity.

3. Lightning is electricity at the extremes

Lightning, driven by static charges generated by storm clouds, is one of the best demonstrations of the power of electricity. According to the United Kingdom's Met Office, the average lightning bolt is the width of a thumb and 2 to 3 miles long (3.2 to 4.8 kilometers). The energy channeled into a lightning bolt heats the air to an unimaginable 54,000 degrees Fahrenheit (30,000 degrees Celsius), which is five times hotter than the surface of the sun.

This happens somewhere on Earth about 44 times a second, according to the Met. Yikes.

4. When thunder roars, plants spark

During electrical storms, plants sometimes react to the electrical fields caused by the storms by discharging tiny sparks of electricity. These sparks can create a faint blue haze known as a corona.

Weirdly, these discharges may affect air quality. In a 2022 study published in the Journal of Geophysical Research: Atmospheres, researchers found that coronas produced high levels of highly reactive chemicals called radicals. Radicals lack electrons and can steal them from nearby atoms, thus altering the chemical compounds around them. This may remove some harmful compounds from the air, but may also create new air pollutants as well, the researchers reported.

5. The brain can power a light bulb

Nerve cells communicate by tiny pulses of electricity, which are triggered by changes in the membranes of nerve cells that allow charged molecules to flow in and out of the cell in response to chemical signals. In other words, the brain generates its own electricity. (This is why an electric shock feels so strange and can cause the body to jerk uncontrollably, as the outside electricity makes the nervous system's electrical machinery go haywire.)

Together, the power generated by all 86 billion neurons in the brain would be enough to power a low-wattage light bulb.

6. The 'hum' of electricity is different around the world

Electricity hums because the current headed to our houses and workplaces is alternating current: The current changes direction multiple times per second. By comparison, direct current, often used for recharging batteries, flows in only one direction. The "mains hum" you hear when near an electrical device is actually a side effect of the vibration of the electromagnet inside the device.

The hum of alternating current varies depending on how quickly the current flip-flops. In the U.S., Canada, and some South American countries, current alternates 60 times per second, while in most of the rest of the world it alternates 50 times per second. The hum is about twice the frequency of the current alternation, Gary Woods, a professor in the practice in the electrical and computer and engineering department at Rice University in Texas, told Live Science. So in the U.S., electricity hums at 120 hertz, or between a B and B-flat two octaves below middle C. In Europe, it hums at 100 hertz, or between an A-flat and G two octaves below middle C.

7. Electricity consumption keeps growing

The world uses a lot of electricity. As of 2019, global electricity consumption reached 22,848 terawatt-hours. To put that into perspective, a terawatt is one trillion watts — that's a whole lot of light bulbs.

Industry consumed about 41% of that total, according to the International Energy Agency (IEA), followed by residential use at around 27% and commercial and public service use at around 21%. The rest went to transportation, including electric vehicles, and other uses. Electricity consumption has been growing steadily since at least the 1970s; 2019's usage was 1.8% greater than 2018's. China is the largest consumer of electricity worldwide, followed by the U.S. and then India.

8. Bees are electric

A swarm of bees may have a shocking effect, and not just because of their stingers. According to research published in the journal iScience in October 2022, bee swarms may generate electrical fields that resemble those produced by a thunderstorm.

Bees are constantly rubbing against plant surfaces and the air, their tiny wings beating hundreds of times per second. As a result, they can easily generate static electricity. Scientists thought that this static was small-scale, until they measured the electrical charge near bee hives as swarms took off. They found that the bees could create an electrical potential gradient of 100 volts per meter, and sometimes up to 1,000 volts per meter — eight times greater than the kind of gradient found in a typical stormcloud. These biologically-created gradients might affect the movements of atmospheric dust and other fine pollutants, the researchers reported.

9. Some bacteria exhale electricity

Deep beneath the ocean floor and far underground on land, bacteria of the genus Geobacter send out tiny snorkels and exhale electricity. It's a weird trick, necessitated by the fact that these bacteria don't have any access to oxygen. Metabolic activity generates excess electrons; humans and other organisms that live an aerobic lifestyle use oxygen to bind to these extra electrons and clear them from the body. But anaerobic organisms — organisms that don't use oxygen — don't have that luxury.

So Geobacter species send out snorkels 100,000 times thinner than a human hair to push electrons out of themselves and to their surroundings, sometimes hundreds of thousands of bacterial body lengths away from the organism. In 2021, researchers found that these teensy electric wires are made of a protein called cytochrome. Colonies of Geobacter can even be used to power electrical devices, but the bacteria don't make much electricity, so the devices have to be tiny.

10. Diamonds need a little jolt to form

Diamonds may be a girl's best friend, but electricity is a diamond's best friend. Scientists reported in 2021 that diamonds, which form deep in Earth's mantle, need a little electrical help to form. It turns out that carbon doesn't turn to shiny bling without a small jolt of about 1 volt, according to the study published in the journal Science Advances.

This probably doesn't present much of a problem in the mantle, where melty rock and other fluids can conduct electrical charges. The tiny electrical field, weaker than a household battery, likely provides extra electrons to jump-start the process of crystallization that forms diamonds.

A rare type of diamond may suggest that water can penetrate deeper into Earth's interior than scientists previously thought. 

Though more than 70% of our planet is covered with water, there is also water in minerals more than 200 miles (322 kilometers) underground, including in the upper mantle, the semi malleable layer that the crust "floats" on top of. Scientists have long thought that as the upper mantle transitions into the hotter, denser lower mantle, minerals can hold far less water. 

But in a new study, published Sept. 26 in the journal Nature Geoscience, researchers found that a diamond contained inclusions, or tiny bits of other minerals, that can hold more water and seem to have existed on the boundary between the upper and lower mantle. The results suggest that there may be water deeper in the Earth than scientists thought, which could affect our understanding of the deep water cycle and plate tectonics.  

The results were unexpected, said lead study author Tingting Gu, who's currently a mineral physicist at Purdue University in Indiana but was a researcher at the Gemological Institute of America in New York City at the time of the study. 

Gu and her colleagues examined type IaB diamonds, a rare type of diamond from the Karowe mine in Botswana that form deep underground and are often in the Earth for a long time. To study the diamond, they used "nondestructive" forms of analysis, including Raman micro-spectroscopy, which uses a laser to noninvasively reveal some of a material’s physical properties, and X-ray diffraction to look at the diamond's internal structure without cutting it open. 

Related: Giant blobs in Earth’s mantle may be driving a 'diamond factory' near our planet’s core

Inside the diamond's inclusions, the researchers found a mineral called ringwoodite, which has the same chemical composition as olivine, the primary material of the upper mantle but forms under such intense temperature and pressure that, until 2014, scientists had only ever found it in a meteorite sample, Gu said. Ringwoodite is typically found in the transition zone between the upper and lower mantle, between around 255 and 410 miles (410 to 660 km) below Earth's surface and can contain much more water than the minerals bridgmanite and ferropericlase, which are thought to dominate the lower mantle, the study authors noted. 

But instead of minerals usually found in the transition zone, surrounding this ringwoodite were forms of minerals typical of the lower mantle. Because the encasing diamond preserved these minerals' properties as they appeared in the deep Earth, the researchers could find the temperatures these the minerals endured and the pressures they were under; they estimated the minerals' depth to be around 410 miles (660 km) below the surface, near the outer boundary of the transition zone. Analysis further revealed that the ringwoodite was likely in the process of breaking down into more typical lower mantle minerals in a hydrous, or water-saturated, environment, hinting that water might penetrate from the transition zone into the lower mantle. 

Although previous research has found some forms of minerals from the lower mantle in diamond inclusions, the combination of materials in this inclusion is unique, the authors noted. It was also unclear from prior findings if these minerals hinted at the presence of water-containing minerals in the lower mantle, the study authors said. Because no one has directly sampled rock deeper than around 7 miles (11 km) beneath the planet's surface, diamond inclusions are one of the few sources of minerals from Earth's mantle. 

The results could have implications for understanding the deep water cycle, or the cycle of water between the planet's surface and deep interior, Gu said. 

"The timescale for the [water cycle] is actually much longer if it can be stored at a deeper place," Gu said, meaning it would take more time for water to renew itself if it were stored deep underground.

The findings also might affect models of plate tectonics. Gu said she hopes scientists will be able to incorporate this study's findings into models of how water in the mantle might influence processes such as Earth's internal convection current. This current powers plate tectonics by unevenly heating the Earth’s mantle, causing hotter parts to rise and shift the Earth’s plates over millions of years. 

Although inclusions are sometimes seen as blemishes in diamonds that make them less desirable, Gu said, they can provide valuable scientific information. 

"Don't be afraid to buy a diamond with an inclusion," she said — you never know what they might contain.  

EDITOR'S NOTE: This article was updated on Sept. 28 to correct the year when scientists first detected ringwoodite in mantle minerals (2014, not 2008) and to amend the timescale for the water cycle in the mantle (longer at deeper depths).

Originally published on Live Science.

Using ultrapowerful lasers, scientists have blasted cheap plastic and transformed it into tiny "nanodiamonds" — and, in doing so, confirmed the existence of an exotic new type of water. .

The findings could potentially reveal the existence of diamond rain on ice giants in our solar system and explain why these frigid worlds have such strange magnetic fields. The laser-blasting technique could also lead to more Earthly applications.

Nanodiamonds are diamonds that measure just a few nanometers, or billionths of a meter. They have both existing and potential applications, such as turning carbon dioxide into other gases and delivering drugs into the body, study co-author Dominik Kraus, a physicist at Helmholtz-Zentrum Dresden-Rossendorf in Germany, told Live Science. 

"Nanodiamonds could also be used as ultrasmall and very precise quantum sensors for temperature and magnetic fields, which may result in a plethora of applications," Kraus said.

The technique could also reduce plastic pollution by creating a financial incentive to clear and transform plastics from the ocean, he said.

An experiment with cool implications for ice giant planets

For many years, planetary scientists have suspected that diamonds form within the frigid interiors of ice giants such as Neptune and Uranus.

If these diamonds do form, they would then "rain" through the interiors of these frozen worlds.

To see whether this process was feasible, the researchers took a sheet of polyethylene terephthalate (PET) plastic — the type found in plastic bottles — and used a high-powered optical laser found at the Matter in Extreme Conditions instrument in the SLAC National Accelerator Laboratory's Linac Coherent Light Source to heat the plastic to around 10,000 degrees Fahrenheit (6,000 degrees Celsius).

This created pressures millions of times greater than that of Earth's atmosphere for just billionths of a second. This bone-crushing pressure shocked the plastic, causing the carbon atoms in the plastic to reconfigure into a crystalline structure, with hydrogen and oxygen drifting through this lattice. 

"Using a powerful X-ray laser, we could look inside the sample and create movies of the chemical reactions happening there," Kraus said. "We saw very efficient formation of nanodiamonds inside the compressed plastics within the timescale of our experiments  —  just a few nanoseconds."

The new research shows that this type of diamond formation may be more common than scientists previously believed, raising the chances that ice giants may sport thick layers of diamonds around their solid cores. 

The experiment also strongly suggests that at the high temperatures and pressures found in the interiors of such icy worlds, an  exotic state of water, called  superionic water ice, emerges.

This strange form of water allows protons to move through a lattice of oxygen atoms. If such superionic water exists on ice giants such as Uranus and Neptune, the movement of protons through this exotic type of matter may help generate the peculiar magnetic fields observed on those planets, Kraus said.

Past calculations suggested that the carbon atoms likely found in planetary interiors would make any superionic water that formed there extremely unstable. 

But "our experiments now show that carbon and water are demixing [the unintended separation of the substances in a mixture] via diamond formation," Kraus said. "Thus, isolated water can be present inside the planets, which makes the formation of superionic water more likely."

And it may soon be possible for a spacecraft to visit our icy neighbors to see whether diamond rain and exotic water actually exist there.

"Hopefully within the next decade, a new NASA space probe will be launched to Uranus, as just defined as the highest priority by the decadal survey," Kraus said.

The findings could also have more commercial applications. Right now, people make nanodiamonds by detonating carbon or blasting larger diamonds to bits with explosives, creating a hodgepodge of different-size diamonds. The new method would be a cleaner way to make diamonds of specific sizes, Kraus said.

The team's research was published Sept. 2 in the journal Science Advances.

Originally published on Live Science.

The boundary zone between Earth's molten metal core and the mantle, its rocky middle layer, might be a diamond factory. 

A new laboratory experiment finds that, under extreme temperatures and pressures, the combination of iron, carbon and water — all potential ingredients found at the core-mantle boundary — can form diamond. If this process also happens deep inside Earth, it might explain some weird quirks of the mantle, including why it has more carbon in it than scientists expect. 

The findings also might help to explain strange structures deep in the core-mantle boundary where waves from earthquakes slow down dramatically. These regions, known as "ultra low velocity zones" are associated with strange mantle structures, including two giant blobs under Africa and the Pacific Ocean; they can be just a few miles across or many hundred. No one knows exactly what they are. Some scientists think they date back 4.5 billion years and are made of materials from the very ancient Earth. But the new research suggests that some of these zones may owe their existence to plate tectonics, which likely started well after Earth's formation, perhaps 3 billion years ago.

"We are adding a new idea that these are not entirely old structures," study lead author Sang-Heon Shim, a geoscientist at Arizona State University, told Live Science.

Simulating the deep Earth 

Where the core meets the mantle, liquid iron rubs up against solid rock. That's as dramatic a transition as the rock-to-air interface at Earth's surface, Shim told Live Science. At such a transition, especially at high pressures and temperatures, strange chemistry can happen. 

What's more, studies that use the reflections of earthquake waves to image the mantle have shown that materials from the crust may penetrate to the core-mantle boundary, some 1,900 miles (3,000 kilometers) below Earth's surface. At subduction zones, tectonic plates push under one another, driving oceanic crust into the subsurface. The rocks in this oceanic crust have water locked in their minerals. As a result, Shim said, it's possible that water exists in the core-mantle boundary and can drive chemical reactions down there. (One theory about the pair of mantle blobs under Africa and the Pacific is that they are made up of distorted oceanic crust that's been pushed deep into the mantle, potentially carrying water with it.)

To test the idea, the researchers pulled together the ingredients available in the core-mantle boundary and pressed them together with anvils made of diamond, generating pressures of up to 140 gigapascals. (That's about 1.4 million times the pressure at sea level.) The researchers also heated the samples to 6,830 degrees Fahrenheit (3,776 degrees Celsius). 

"We monitored what kind of reaction was happening when we heated the sample," Shim said. "Then we detected diamond, and we detected an unexpected element exchange between rock and the liquid metal." 

Churning out diamonds 

Under the pressure and temperature of the core-mantle boundary, Shim said, water behaves very differently than it does on Earth's surface. The hydrogen molecules split from the oxygen molecules. Because of the high pressure, hydrogen gravitates toward iron, which is the metal that makes up most of the core. Thus, the oxygen from water stays in the mantle, while the hydrogen melds with the core. 

When this happens, the hydrogen seems to push aside other light elements in the core, including, crucially, carbon. This carbon gets booted out of the core and into the mantle. At the high pressures present in the core-mantle boundary, carbon's most stable form is diamond. 

"That's how diamond forms," Shim said. 

These aren't the same diamonds that might sparkle in an engagement ring; most diamonds that make their way to the surface, and ultimately become someone's jewelry, form a few hundred kilometers deep, not a few thousand. But the core-mantle diamonds are likely buoyant and could get swept throughout the crust, distributing their carbon as they go. 

The mantle has three to five times more carbon than researchers would expect based on the proportion of elements in stars and other planets. The diamonds found in this layer of Earth might explain the discrepancy, Shim said. He and his team calculated that if even 10% to 20% of the water in oceanic crust makes it to the core-mantle boundary, it could churn out enough diamonds to explain the levels of carbon in the crust. 

If that's the case, many of the low-velocity zones in the mantle might be areas of water-driven melt, triggered by the churn of the oceanic plates deep into the planet. 

Proving this process happens thousands of kilometers below the surface is the next challenge. There are a couple of ways to look for evidence, Shim said. 

One is to search for structures within the core-mantle boundary that could be clusters of diamonds. Diamonds are dense and would transmit earthquake waves quickly, so researchers would need to find high-velocity zones alongside the already-discovered regions where waves travel slowly. Other researchers at Arizona State University are investigating this possibility, Shim said, but the work isn't yet published.

Another option is to study diamonds that may come from very deep in Earth's mantle. These diamonds can sometimes make it to the surface with tiny pockets, or inclusions, full of minerals that can form only under very high pressure. 

Even the famed Hope Diamond may have formed very deep in the planet's mantle. When scientists claim to have discovered very deep diamonds, those assertions are often controversial, Shim said, in part because the inclusions are so tiny that there is barely any material to measure. But it might be worth looking for core-mantle boundary inclusions, he said. 

"That would be some kind of a discovery, if someone could find evidence for that," he said.

The researchers reported their findings Aug. 11 in the journal Geophysical Research Letters.

Originally published on Live Science.

While studying diamonds inside an ancient meteorite, scientists have found a strange, interwoven microscopic structure that has never been seen before. 

The structure, an interlocking form of graphite and diamond, has unique properties that could one day be used to develop superfast charging or new types of electronics, researchers say. 

The diamond structures were locked inside the Canyon Diablo meteorite, which slammed into Earth 50,000 years ago and was first discovered in Arizona in 1891. The diamonds in this meteorite aren't the kind most people are familiar with. Most known diamonds were formed around 90 miles (150 kilometers) beneath Earth's surface, where temperatures rise to more than 2,000 degrees Fahrenheit (1,093 degrees Celsius). The carbon atoms within these diamonds are arranged in cubic shapes.

By contrast, the diamonds inside the Canyon Diablo meteorite are known as lonsdaleite — named after British crystallographer Dame Kathleen Lonsdale, University College London's first female professor — and have a hexagonal crystal structure. These diamonds form only under extremely high pressures and temperatures. Although scientists have successfully made lonsdaleite in a lab — using gunpowder and compressed air to propel graphite disks 15,000 mph (24,100 km/h) at a wall — lonsdaleite is otherwise formed only when asteroids strike Earth at enormously high speeds. 

Related: Diamond hauled from deep inside Earth holds never-before-seen mineral 

While studying lonsdaleite in the meteorite, the researchers found something odd. Instead of the pure hexagonal structures they were expecting, the researchers found growths of another carbon-based material called graphene interlocking with the diamond. These growths are known as diaphites, and inside the meteorite, they form in a particularly intriguing layered pattern. In between these layers are "stacking faults," which mean the layers don't line up perfectly, the researchers said in a statement.  

Finding diaphites in the meteoritic lonsdaleite suggests that this material can be found in other carbonaceous material, the scientists wrote in the study, which means it could be readily available to use as a resource. The finding also gives the researchers a better sense of the pressures and temperatures needed to create the structure. 

Graphene is made of a one-atom-thick sheet of carbon, arranged in hexagons. Although research on this material is still ongoing, the material has many potential applications. Because it is both as light as a feather and as strong as a diamond; both transparent and highly conductive; and 1 million times thinner than a human hair, it could one day be used for more targeted medicines, tinier electronics with lighting-fast charging speeds, or faster and bendier technology, the researchers said.

And now that researchers have discovered these graphene growths inside meteorites, it's possible to learn more about how they form — and thus how to make them in the lab.

"Through the controlled layer growth of structures, it should be possible to design materials that are both ultra-hard and also ductile, as well as have adjustable electronic properties from a conductor to an insulator," Christoph Salzmann, a chemist at University College London and co-author of a paper describing the research, said in the statement. 

The strange new structures were described July 22 in the journal Proceedings of the National Academy of Sciences.

Originally published on Live Science.

Carbon is an incredible element. Arrange carbon atoms in one way, and they become soft, pliable graphite. Rejigger the arrangement, and — presto! — the atoms form diamond, one of the hardest materials in the world.

Carbon is also the key ingredient for most life on Earth; the pigment that made the first tattoos; and the basis for technological marvels such as graphene, which is a material stronger than steel and more flexible than rubber. [See Periodic Table of the Elements]

Carbon occurs naturally as carbon-12, which makes up almost 99% of the carbon in the universe; carbon-13, which makes up about 1%; and carbon-14, which makes up a minuscule amount of overall carbon but is very important in dating organic objects.

Carbon: Fast facts

• Atomic Number (number of protons in the nucleus): 6
• Atomic Symbol (on the Periodic Table of Elements): C
• Atomic Weight (average mass of the atom): 12.0107
• Density: 2.2670 grams per cubic centimeter
• Phase at Room Temperature: Solid
• Melting Point: 6,422 degrees Fahrenheit (3,550 degrees Celsius)
• Boiling Point: 6,872 F (3,800 C) (sublimation)
• Number of isotopes: 15 total; two stable isotopes, which are atoms of the same element with a different number of neutrons.
• Most common isotopes: carbon-12 (6 protons, 6 neutrons and 6 electrons) and carbon-13 (6 protons, 7 neutrons and 6 electrons)

How carbon forms: From stars to life

As the sixth-most abundant element in the universe, carbon forms in the belly of stars in a reaction called the triple-alpha process, according to the Swinburne Center for Astrophysics and Supercomputing. 

In older stars that have burned most of their hydrogen, leftover helium accumulates. Each helium nucleus has two protons and two neutrons. Under very hot temperatures — greater than 100,000,000 Kelvin (179,999,540.6 F) — the helium nuclei begin to fuse, first as pairs into unstable 4-proton beryllium nuclei, and eventually, as enough beryllium nuclei blink into existence, into a beryllium plus a helium. The end result: Atoms with six protons and six neutrons — carbon.

Carbon is a pattern maker. It can link to itself, forming long, resilient chains called polymers. It can also bond with up to four other atoms because of its electron arrangement. Atoms are arranged as a nucleus surrounded by an electron cloud, with electrons zinging around at different distances from the nucleus. Chemists conceive of these distances as shells, and define the properties of atoms by what is in each shell, according to the University of California, Davis. Carbon has two electron shells, with the first holding two electrons and the second holding four out of a possible eight spaces. When atoms bond, they share electrons in their outermost shell. Carbon has four empty spaces in its outer shell, enabling it to bond to four other atoms. (It can also bond stably to fewer atoms by forming double and triple bonds.)

In other words, carbon has options. And it uses them: Nearly 10 million carbon compounds have been discovered, and scientists estimate that carbon is the keystone for 95% of known compounds, according to the website Chemistry Explained. Carbon's incredible ability to bond with many other elements is a major reason that it is crucial to almost all life. 

Carbon's discovery is lost to history. The element was known to prehistoric humans in the form of charcoal. Carbon as coal is still a major source of fuel worldwide, providing about 37% of the world's electricity, according to the World Coal Association. Coal is also a key component in steel production, while graphite, another form of carbon, is a common industrial lubricant.

Carbon-14 is a radioactive isotope of carbon used by archaeologists to date objects and remains. Carbon-14 is naturally occurring in the atmosphere. Plants take it up in respiration, in which they convert sugars made during photosynthesis back into energy that they use to grow and maintain other processes, according to the Iowa State University Center for Nondestructive Evaluation. Animals incorporate carbon-14 into their bodies by eating plants or other plant-eating animals. Carbon-14 has a half-life of 5,730 years, meaning that after that time, half of the carbon-14 in a sample decays away, according to the University of Arizona.

Because organisms stop taking in carbon-14 after death, scientists can use carbon-14's half-life as a sort of clock to measure how long it has been since the organism died. This method works on once-living organisms, including objects made of wood or other plant material.

Carbon: Who knew?

• Carbon gets its name from the Latin word carbo, which means "coal."
• Diamonds and graphite are among the hardest and softest natural materials known, respectively. The only difference between the two is their crystal structure.
• Carbon makes up 0.032% of the Earth's lithosphere (crust and outer mantle) by weight, according to the Encyclopedia of Earth. A rough estimate of the weight of the lithosphere by La Salle University geologist David Smith is 300,000,000,000,000,000,000,000 (or 3*10^23) pounds, making the approximate weight of carbon in the lithosphere 10,560,000,000,000,000,000,000 (or 1.056*10^22) pounds.
• Carbon dioxide (a carbon atom plus two oxygen atoms) makes up about 0.04% of Earth's atmosphere, according to the National Oceanic & Atmospheric Administration (NOAA) — an increase over pre-industrial times, because of the burning of fossil fuels.
• Carbon monoxide (a carbon atom plus one oxygen atom) is an odorless gas produced from the burning of fossil fuels. Carbon monoxide kills by binding to hemoglobin, the oxygen-carrying compound in the blood. Carbon monoxide bonds to hemoglobin 210 times more strongly than oxygen binds to hemoglobin, effectively crowding out oxygen and suffocating the tissues, according to a 2001 paper in the Journal of the Royal Society of Medicine.
• Diamond, the flashiest version of carbon, is formed under great pressure deep in the Earth's crust. The largest gem-quality diamond ever found was the Cullinan diamond, which was discovered in 1905, according to the Royal Collection Trust. The uncut diamond was 3,106.75 carats. The largest gem cut from the stone, at 530.2 carats, is one of the Crown Jewels of the United Kingdom and is known as the Great Star of Africa.
• The tattoos of Ötzi the Iceman, a 5,300-year-old corpse found frozen in the Alps, were inked from carbon, according to a 2009 study in the Journal of Archaeological Science. Small incisions in the skin were made, and charcoal rubbed in, perhaps as part of an acupuncture treatment.

Ongoing research

Carbon is a long-studied element, but that doesn't mean there isn't more to discover. In fact, the same element that our prehistoric ancestors burned as charcoal may be the key to next-generation tech materials.

In 1985, Rick Smalley and Robert Curl of Rice University in Texas and their colleagues discovered a new form of carbon. By vaporizing graphite with lasers, the scientists created a mysterious new molecule made of pure carbon, according to the American Chemical Society. This molecule turned out to be a soccer-ball-shaped sphere made of 60 carbon atoms. The research team named their discovery the buckminsterfullerene after an architect who designed geodesic domes. The molecule is now more commonly known as the "buckyball." The researchers who discovered it won a Nobel Prize in Chemistry in 1996. Buckyballs have been found to inhibit the spread of HIV, according to a study published in 2009 in the Journal of Chemical Information and Modeling; medical researchers are working to attach drugs, molecule-by-molecule, to buckyballs in order to deliver medicine directly to sites of infection or tumors in the body; this includes research by Columbia University, Rice University and others. In 2021, researchers led by Yongjun Tian of Yanshan University in China found that by compressing buckyballs, they could make the hardest non-crystalline material ever seen, almost as hard as diamond.

Other new, pure carbon molecules — called fullerenes — have been discovered, including elliptical-shaped "buckyeggs" and carbon nanotubes with amazing conductive properties. Carbon chemistry is still hot enough to capture Nobel Prizes: In 2010, researchers from Japan and the United States won one for figuring out how to link carbon atoms together using palladium atoms, a method that enables the manufacture of large, complex carbon molecules, according to the Nobel Foundation.

Scientists and engineers are working with these carbon nanomaterials to build materials straight out of science-fiction. A 2010 paper in the journal Nano Letters reported the invention of flexible, conductive textiles dipped in a carbon nanotube "ink" that could be used to store energy, perhaps paving the way for wearable batteries, solar cells and other electronics. The ink is now commercially available from chemical supply companies. 

Perhaps one of the hottest areas in carbon research today, however, involves the "miracle material" graphene. Graphene is a sheet of carbon only one atom thick. It's the strongest material known while still being ultralight and flexible. And it conducts electricity better than copper. Scientists are still discovering new properties of graphene. In 2020, for example, researchers reported in the journal Nature Physics that by stacking graphene in the right way, they could make it magnetic. 

Mass-producing graphene is a challenge, though researchers in April 2014 reported that they could make large amounts using nothing but a kitchen blender. In 2020, scientists at TU Delft in the Netherlands developed a mathematical model to guide large-scale production. If scientists can figure out how to make lots of graphene easily, the material could become huge in tech. Imagine flexible, unbreakable gadgets that also happen to be paper-thin. Carbon has come a long way from charcoal and diamonds, indeed.

Carbon nanotubes

A carbon nanotube (CNT) is a minuscule, straw-like structure made of carbon atoms. These tubes are extremely useful in a wide variety of electronic, magnetic and mechanical technologies. The diameters of these tubes are so tiny that they are measured in nanometers. A nanometer is one-billionth of a meter — about 10,000 times smaller than a human hair.

Carbon nanotubes are at least 100 times stronger than steel, but only one-sixth as heavy, so they can add strength to almost any material, according to UnderstandingNano.com They are also better than copper at conducting electricity and heat.

Nanotechnology is being applied to the quest to turn seawater into drinking water. In a new study, scientists at Lawrence Livermore National Laboratory (LLNL) have developed a carbon nanotube process that can take the salt out of seawater far more efficiently than traditional technologies.

For example, traditional desalination processes pump in seawater under high pressure, sending it through reverse osmosis membranes. These membranes then reject all large particles, including salts, allowing only clean water to pass through. However, these desalination plants are very expensive and can only process about 10 percent of a county's water needs, according to LLNL.

In the nanotube study, the scientists mimicked the way biological membranes are structured: essentially a matrix with pores inside the membrane. They used nanotubes that were particularly small — more than 50,000 times thinner than a human hair. These tiny nanotubes allow for a very high flux of water but are so narrow that only one water molecule can pass through the tube at a time. And most importantly, the salt ions are too big to fit through the tube.

The researchers think the new discovery has important implications for the next generation of both water purification processes and high-flux membrane technologies.

Additional reporting by Traci Pedersen, Live Science contributor.

Additional resources

• Learn more about the element carbon at the website of the Jefferson Lab National Accelerator Facility.
• NASA's Earth Observatory has a thorough description of the carbon cycle, from how it is formed to its cycling through Earth's ecosystems, with some of that carbon being emitted to the atmosphere.
• Learn more about carbon and diamonds at the Smithsonian Institution.

Bibliography

King, H. "Diamond." Geology.com. Accessed March 10, 2022.

Tiwari, S.K., et al. "Graphene research and their outputs: Status and prospect," Journal of Science: Advanced Materials and Devices, Vol. 5, No. 1, 10-29, March 2020. https://doi.org/10.1016/j.jsamd.2020.01.006.

Rao, R., et al. "Carbon Nanotubes and Related Nanomaterials: Critical Advances and Challenges for Synthesis toward Mainstream Commercial Applications," ACS Nano 2018, 12, 12, 11756–11784, December 5, 2018. https://doi.org/10.1021/acsnano.8b06511

One lucky millionaire, or billionaire, will soon be able to get their hands on a one-of-a-kind black diamond, known as the "Enigma," when the shadowy gem goes up for auction next month. But they might not be getting exactly what they paid for. 

The Enigma has been artificially cut to weigh exactly 555.55 carats (111 grams) and has 55 black facets. It is currently the largest cut black diamond in the world, according to Guinness World Records. 

"The shape of the diamond is based on the [five-fingered] Middle-Eastern palm symbol of the Khamsa, which stands for strength and protection," jewelry specialist Sophie Stevens told the Associated Press. (Khamsa means "five" in Arabic.)

Auction house Sotheby's unveiled the unique gemstone in Dubai, United Arab Emirates, on Jan. 17. The diamond will also be displayed in Los Angeles before arriving in London to be auctioned on Feb. 3. Sotheby's estimates the Enigma will eventually sell for at least $6.8 million. Cryptocurrency bids will also be accepted by the auction house.

Related: Sinister sparkle gallery: 13 mysterious and cursed gemstones

In addition to the diamond's unusual color and unique weight and shape, one of the main selling points is that it may have originated from space. According to a statement from Sotheby's, the Enigma is "thought to have been created either from a meteoric impact or having actually emerged from a diamond-bearing asteroid that collided with Earth." However, black-diamond experts have told Live Science that they are skeptical of the company's claim and said the gemstone probably originated on Earth. 

Black diamonds 

Black diamonds have high densities of opaque mineral inclusions, particularly graphite — a dark gray form of carbon with a hexagonal structure, unlike diamond, which is a form of carbon in a tetrahedral shape — and metal sulfides, said Peter Heaney, a geoscience professor at Penn State and a black-diamond expert.

Sotheby's describes the Enigma as a carbonado diamond, a Portuguese name given to black diamonds in the 19th century. However, "not all black diamonds are carbonados," Heaney told Live Science. Rather, a carbonado is a type of black diamond that is both polycrystalline, meaning multiple crystals fused into a single gem, and porous, Heaney said. Carbonado diamonds also contain uranium-rich phosphates, which generate "radiation halos" around the pores, or holes, on their surfaces. This trait makes them highly absorptive of white light, making them completely opaque and much darker than other black diamonds, Heaney said.

"Carbonados are superhard and supertough," due to their polycrystalline and porous properties, Heaney said. This makes them perfect for industrial use, such as drill bits used in the oil industry for penetrating hard igneous rocks, he added. 

Considering its large size, the Enigma is most likely a true carbonado, Heaney said. After looking at magnified images on his computer, he believes the Enigma is pitted (meaning it is porous), which is suggestive of a carbonado, but it is hard to tell for sure because the diamond has been cut. It is also hard to tell from the images if the diamond is truly opaque, he added. 

Uncertain origins  

All known carbonados have been found in either Brazil or the Central African Republic and date back to roughly 3.8 billion years ago, Heaney said. During this time, the two countries were part of the same supercontinent known as Rodinia,  exactly how and where the diamonds formed is still unclear. 

It is possible that carbonados do have an extraterrestrial origin, as the auction house claims. Scientists have found black diamonds created from the impacts of meteorites in the past, but these diamonds are normally very small, which makes it an unlikely origin for true carbonados as large as the Enigma, Heaney said. "I would be quite surprised if a diamond that large originated from a meteorite impact," he said.

Other space-based theories speculate that fully formed carbonados could already exist in some asteroids that crash to Earth or even that the diamonds are formed by powerful stellar explosions called supernovas, but there is not enough evidence to support either of those ideas, Heaney said.

"I believe the chances of carbonado specimens we’ve studied and seen data for being from outer space are low," Richard Ketcham, a geoscientist at the University of Texas at Austin, who has also studied black diamonds, told Live Science. The idea of carbonados originating from space is the "minority viewpoint among those who study them," he added. 

Instead, Heaney and Ketcham believe the most likely origin of carbonados is here on Earth. However, the exact mechanism that forms these black diamonds isn't yet clear. Most diamonds form when high pressures in Earth's middle layer, or mantle, crush organic carbon. But the oldest carbonados potentially predate life on Earth — and, therefore, organic carbon — which makes it unlikely that they formed this way.  

After searching for a definitive origin of carbonados for close to a decade, Heaney has come up "empty-handed" and, as a result, believes that more research is needed. "I am not persuaded that anyone has fully answered the question," he said. 

Because the Enigma has been cut, it is also much harder to be able to tell how it may have originated, Ketcham said. "The outer surfaces of carbonados likely have clues bearing on their origin, which are now probably lost," in the Enigma, he added. The auction house's claim that the Enigma came from space, therefore, seems dubious.

Regardless of how the diamond came into existence, Heaney hopes that whoever ends up buying the Enigma will put it on public display rather than hiding it away in a private collection. "Many great diamonds have not seen the light of day for decades," Heaney said. "Museums cannot compete with billionaires for the purchase of natural wonders."

Originally published on Live Science.

Diamonds are the most sought-after and admired gemstones, with a sparkling brilliance that sets them apart from all other jewelry. That’s as true today, when diamonds are mined on an industrial scale, as it was thousands of years ago when they were a much rarer commodity. 

According to the Gemological Institute of America (GIA), the Roman historian Pliny wrote in the first century AD, “Diamond is the most valuable, not only of precious stones, but of all things in this world” . So where do diamonds come from, and what makes them so special?

Diamonds were first discovered in around 2500 BCE in India, according to the Cape Town Diamond Museum.. These diamonds weren’t mined in the modern sense – they were simply collected from the sediment in rivers and streams. 

Their striking appearance made them highly desirable, and by the 4th century BC they were being traded with other parts of the world. Their extreme rarity meant that only the very wealthiest could afford them, and diamonds became the ultimate status symbol among the medieval elite. It was only in the 19th century, when more extensive diamond deposits were found in South Africa, that they became accessible to the general public, according to the museum.

What diamonds are made of

Diamond crystals are made from just one chemical element, carbon according to the GIA. The same is true of graphite, which is a much commoner mineral that couldn’t be more different in appearance and properties. 

Graphite is what pencil lead is made from, and it’s so soft that it rubs off onto the page when you write with it. Diamond, on the other hand, is one of the hardest known substances – so hard it can only be scratched with another diamond. The difference lies in the arrangement of carbon atoms. 

In graphite they form planar sheets, which can easily glide against each other, while in diamond they form a rigid three-dimensional structure,according to the Atlantic . The hardness of diamond means it has other, more practical, uses besides jewelry, particularly for technological uses such as cutting, and drilling, according to an article published in the 14th International Congress for Applied Mineralogy (ICAM2019). 

How diamonds are formed

While carbon normally exists as graphite on the Earth’s surface, it can form diamond at much greater depths – a hundred miles or more – where temperatures and pressures are far higher, according to Smithsonian Magazine. 

In a few places diamond-bearing material from these depths has been carried up to the surface by volcanic eruptions – and some of this material was subsequently washed into the river beds where diamonds were first found. Today, however, most diamonds come from directly mining the diamond-bearing rock, which is called kimberlite after the mining town of Kimberley in South Africa where it was first found.

How diamonds form in kimberlite pipes

Diamonds form deep inside the Earth, but they can reach the surface through volcanic pipes.

How diamonds are graded

Not all diamonds are the same. Some aren’t suitable for use in jewelry, and find their way into industrial applications. Even gem-quality diamonds vary considerably, and are typically graded according to the “4 Cs” of cut, color, clarity and carat according to the American Gem Society. The first three are self-explanatory, while “carat” is a measure of weight equivalent to 200 milligrams.

Why diamonds are expensive

At one time diamonds were expensive because of their rarity, but today they’re actually less scarce than many other gemstones, such as rubies or sapphires, according to the International Gem Society.  However, diamond production involves a costly processing chain all the way from mining to polishing. On top of that, there’s a huge worldwide demand for diamonds, due to their widespread use in engagement rings – a “tradition” which originated in a clever marketing campaign in the 1930s, according to the BBC.

When James Bond creator Ian Fleming wrote Diamonds Are Forever in 1956, he might have been quoting an age-old proverb. But it turns out this too was a marketing slogan that had been coined less than a decade earlier. And it’s not even true, because diamond is an unstable form of carbon that eventually degrades to graphite – although it takes millions of years to do so, according to Dr Christopher S. Baird of West Texas A&M University.

How diamonds reflect light

Where diamonds are found

Historically, the epicentre of diamond mining activity was in Africa, but more recently diamonds have been found in many other parts of the world according to geologist Hobart M. King of Geology.com. 

Africa still plays a leading role, with countries such as Botswana, Angola, South Africa, Namibia and the Democratic Republic of the Congo all producing more than a million carats of diamonds each year. However, the combined output of those five countries – around 30 million carats – is exceeded by two non-African countries, Russia and Canada, which produce 41 million carats between them. And many other countries produce smaller quantities of gem-quality diamonds, including Australia, Brazil and Guyana.

Diamonds in the sky

Although we think of diamonds as being very rare, the conditions which produce them occur quite widely throughout the universe. As a result, there really are “diamonds in the sky”. We have direct evidence of this in the form of diamond-containing meteorites, which originated very early in the history of the solar system, according to Space.com.

Fast-forwarding to the present day, Earth isn’t the only planet in the solar system where diamonds can be found. Deep inside the atmospheres of the ice giants Neptune and Uranus, carbon can be compressed to the extreme pressures and temperatures needed to form diamonds, according to Space.com. These then sink down to the planetary cores in the form of a spectacular "diamond rain".

Looking beyond the solar system, it may be possible to find planets with many more diamonds than the Earth. It’s conjectured that planets orbiting carbon-rich stars would have a much higher diamond content than our own planet. 

A few years ago there was a flurry of excitement around one particular exoplanet, 55 Cancri e, which was hailed as the “diamond planet” because it was believed to be especially rich in diamonds, Space.com reported. However, while that theory hasn’t been completely disproved, it seems much less likely now.

Lab-grown diamonds

There’s nothing mystical or supernatural about diamonds – they’re simply the form that carbon takes under certain conditions of temperature and pressure. 

Natural diamonds were formed where these conditions exist inside the Earth, but it’s also possible to create the necessary conditions artificially. This has been done on a commercial scale to make synthetic diamonds since the 1950s, according to materials engineer Dr Dmitri Kopeliovich.. One approach, called the high pressure, high temperature (HPHT) technique, attempts to mimic the natural process as closely as possible. 

An alternative, called chemical vapour deposition (CVD), requires less extreme temperatures and pressures. At first synthetic diamonds were poor in quality, and only suitable for industrial purposes, but today they can be made attractive enough to use in jewelry, according to the Gemological Institute of America.

Additional resources

To learn more about diamond cutting and polishing, you can follow the step-by-step process on the Cape Town Diamond Museum website. Or find out about how the most colorful gemstones on Earth form in this TED Talk.

Bibliography

"Impact Diamonds: Types, Properties and Uses". 14th International Congress for Applied Mineralogy (2019). https://link.springer.com/chapter/10.1007/978-3-030-22974-0_41

"On the Origin of Natural Diamonds". American Astronomical Society. https://adsabs.harvard.edu/pdf/1961ApJ...134..995W

"The ice layer in Uranus and Neptune– diamonds in the sky?" Nature (1981). https://www.nature.com/articles/292435a0

Within a diamond hauled from deep beneath Earth's surface, scientists have discovered the first example of a never-before-seen mineral.

Named davemaoite after prominent geophysicist Ho-kwang (Dave) Mao, the mineral is the first example of a high-pressure calcium silicate perovskite (CaSiO3) found on Earth. Another form of CaSiO3, known as wollastonite, is commonly found across the globe, but davemaoite has a crystalline structure that forms only under high pressure and high temperatures in Earth's mantle, the mainly solid layer of Earth trapped between the outer core and the crust.

Davemaoite has long been expected to be an abundant and geochemically important mineral in Earth's mantle. But scientists have never found any direct evidence of its existence because it breaks down into other minerals when it moves toward the surface and pressure decreases. However, analysis of a diamond from Botswana, which formed in the mantle around 410 miles (660 kilometers) below Earth's surface, has revealed a sample of intact davemaoite trapped inside. As a result, the International Mineralogical Association has now confirmed davemaoite as a new mineral.

Related: Earth's 8 biggest mysteries

"The discovery of davemaoite came as a surprise," lead author Oliver Tschauner, a mineralogist at the University of Nevada, Las Vegas, told Live Science. 

Tschauner and his colleagues uncovered the davemaoite sample with a technique known as synchrotron X-ray diffraction, which focuses a high-energy beam of X-rays on certain spots within the diamond with microscopic precision. By measuring the angle and intensity of the returning light, researchers can decipher what's inside, Tschauner said. The sample of davemaoite within the diamond was just a few micrometers (millionths of a meter) in size, so less-powerful sampling techniques would have missed it, he added.

Davemaoite is believed to play an important geochemical role in Earth's mantle. Scientists theorize that the mineral may also contain other trace elements, including uranium and thorium, which release heat via radioactive decay. Therefore, davemaoite may help to generate a substantial amount of heat in the mantle, Tschauner said.

In a 2014 study published in the journal Science, researchers described another theoretical high-pressure mineral from the mantle, known as bridgmanite. However, the sample of bridgmanite did not originate from the mantle but rather inside a meteorite. The discovery of davemaoite shows that diamonds can form farther down in the mantle than previously thought, and it suggests that they might be the best place to look for more new minerals from the mantle, Tschauner said.

"The work by Tschauner et al. inspires hope in the discovery of other difficult high-pressure phases in nature," Yingwei Fe, a geophysicist at the Carnegie Institution for Science in Washington, D.C., who was not involved in the study, said in a related Science article. "Such direct sampling of the inaccessible lower mantle would fill our knowledge gap in chemical composition of the entire mantle of our planet."

The study was published online Nov. 11 in the journal Science.

Originally published on Live Science.

Diamonds may be the strongest known natural material, but researchers have just created some stiff competition.

By firing a dime-sized graphite disk at a wall at 15,000 mph (24,100 km/h), scientists momentarily created a hexagonal diamond that is both stiffer and stronger than the natural, cubic kind. 

Hexagonal diamonds, also known as Lonsdaleite diamonds, are a special type of diamond with carbon atoms arranged in a hexagonal pattern. Formed when graphite is exposed to extreme heat and stress, such as at meteor impact sites, the rare material has long been theorized to be stronger than ordinary cubic diamonds. 

However, as the hexagonal diamonds found in impact craters contain too many impurities, scientists have never accurately measured their properties. 

Related content: Sinister sparkle gallery: 13 mysterious & cursed gemstones

Now, researchers have not only forged the hexagonal diamonds but also measured their stiffness — the ability to resist changing shape when squashed or stretched — with a combination of sound waves and laser light.

"Diamond is a very unique material," study co-author Yogendra Gupta, director of the Washington State University Institute for Shock Physics, said in a statement. "It is not only the strongest — it has beautiful optical properties and a very high thermal conductivity. Now we have made the hexagonal form of diamond, produced under shock compression experiments, that is significantly stiffer and stronger than regular gem diamonds."

Cubic diamonds usually form more than 90 miles (150 kilometers) beneath Earth’s surface, under extreme pressures many times greater than the crushing depths of the deep ocean, and temperatures beyond 2,732 degrees Fahrenheit (1,500 degrees Celsius). But to form hexagonal diamonds, the researchers emulated the high-energy impact of a meteor strike, using gunpowder and compressed air to launch the graphite disks at incredible speeds. As the disks slammed into a wall, the shockwaves of the impact rapidly transformed the disks into hexagonal diamonds.

To measure the diamonds’ strength and stiffness in the fraction of a second before the minerals were smashed to smithereens, the researchers emitted a  sound wave and measured how quickly it traveled through the hexagonal diamonds with a laser.  (The sound waves cause the diamond density to fluctuate as it moves through, which affects the path length of the laser beam.) The stiffer a material is, the faster sound moves through it. 

It's difficult to tell if the hexagonal diamonds are harder than the average diamond. Hardness is a measure of how difficult it is to scratch a material’s surface, and the hexagonal diamonds didn’t exist long enough for the scientists to scratch them. 

Right now scientists haven't figured out a way to create more long-lived hexagonal diamonds in the lab, but if a method is discovered, the researchers anticipate a range of uses for them — from more effective drill bit tips, to fancier engagement rings.

"If someday we can produce them and polish them, I think they'd be more in-demand than cubic diamonds," Gupta said. "If somebody said to you, 'Look, I'm going to give you the choice of two diamonds: one is a lot more rare than the other one.' Which one would you pick?"

The researchers published their findings March 31 in the Journal Physical Review B.

Originally published on Live Science.

Before diamonds can begin growing deep underground in Earth's mantle, they need a little zap from an electric field, a new study finds.

In lab-based experiments, scientists mimicked conditions in the mantle — the layer just beneath Earth's crust — and found that diamonds grew only when exposed to an electric field, even a weak one of about 1 volt, according to the study, which was published online Jan. 20 in the journal Science Advances.

"Our results clearly show that electric fields should be considered as an important additional factor that influences the crystallization of diamonds," study lead researcher Yuri Palyanov, a diamond specialist at the V.S. Sobolev Institute of Geology and Mineralogy of the Siberian Branch of the Russian Academy of Sciences, and at Novosibirsk State University, said in a statement. 

Related: Photos: Dazzling minerals and gems

Diamonds are made of carbon atoms aligned in a particular crystal structure. They form more than 90 miles (150 kilometers) under Earth's surface, where pressures reach several gigapascals and temperatures can soar upward of 2,732 degrees Fahrenheit (1,500 degrees Celsius). But many factors behind the "birth" of this gem — prized for its polished beauty and extreme hardness — are a mystery; so a team of Russian and German scientists looked at one factor in particular: underground electric fields.

The researchers gathered the starting ingredients needed to make a diamond — carbonate and carbonate-silicate powders that are similar to carbonate-rich melts abundant in the mantle. They put these powders in an artificial mantle in their lab and subjected them to pressures of up to 7.5 gigapascals and temperatures of up to 2,912 F (1,600 C), and electrode-powered electric fields ranging from 0.4 to 1 volt. After varying periods lasting up to 40 hours, diamonds (and their softer carbon-based cousin, graphite) formed, but only when the researchers set up an electric field of about 1 volt — which is weaker than most household batteries. 

Moreover, the diamonds and graphite formed only at the cathode, or the negative part of the electric field. This spot provides electrons to jumpstart a chemical process — mainly, so that certain carbon-oxygen compounds in the carbonates can undergo a series of reactions to become carbon dioxide and, eventually, the carbon atoms that can form a diamond.

The synthetic diamonds were small, with diameters no larger than 0.007 inches (200 micrometers, or one-fifth of a millimeter), but they were surprisingly similar to natural diamonds — both have an octahedral shape and tiny amounts of other elements and compounds, including a relatively high nitrogen content and silicate-carbonate inclusions, also known as diamond "birthmarks" or imperfections, the researchers said.

These experiments suggest that local electrical fields play a pivotal role in diamond formation in Earth's mantle, the researchers said. This local voltage is likely created by rock melts and fluids in the mantle that have high electrical conductivity, but it's unclear how strong these electrical fields are, Chemistry World reported.

"Our approach is of interest for the development of new methods for producing diamonds and other carbon materials with special properties," Palyanov said in another statement.

Originally published on Live Science.

Diamonds are forever, or so the slogan goes. But with the proper application of heat and enough oxygen, a diamond can go up in smoke.

Diamonds are carbon, just like coal. It takes a bit more to get them burning and keep them burning than coal, but they will burn, as numerous YouTube demonstrations will attest. The trick is to create the right conditions so that a solid diamond can react with the oxygen required to fuel a fire.

"You have to convert that solid [carbon] into a gas form, so it can react with the air to make a flame," said Rick Sachleben, a retired chemist and member of the American Chemical Society.

Related: Which is rarer: Gold or diamonds?

The best way to do that? Heat — and lots of it. In room temperature air, diamonds ignite at around 1,652 degrees Fahrenheit (900 degrees Celsius), according to West Texas A&M University physicist Christopher Baird. For comparison, a high-volatile coal (coal containing a relatively high amount of easily released gases) ignites at about 1,233 F (667 C), whereas wood ignites at 572 F (300 C) or less, depending on the type.

When first heated, a diamond will glow red, then white. The heat enables a reaction between the surface of the diamond and the air, converting the carbon to the colorless and odorless gas carbon monoxide (a carbon atom plus an oxygen atom).

"The carbon plus the oxygen to make carbon monoxide generates heat; the carbon monoxide reacting with the oxygen generates more heat; the rising heat causes the carbon monoxide to move away, so more oxygen is brought in," he told Live Science.

That fire, however, will amount to only a glow. Nurturing a flame on the surface of a diamond usually requires an extra boost: 100% oxygen rather than room air, which is only 22% oxygen. This increase in concentration gives the reaction all that it needs to self-perpetuate. The carbon monoxide rising from the diamond ignites in the presence of oxygen, creating a fire that seems to dance on the stone's surface.

"Almost everything burns incredibly in pure oxygen," Sachleben said.

Even without pure oxygen, diamonds can be damaged by flame, according to the Gemological Institute of America (GIA). Typically, a diamond caught in a house fire or by an overzealous jeweler's torch will not go up in smoke, but instead will combust on the surface enough to look cloudy and white. Cutting away the burnt portions will reveal a smaller, but once again crystal-clear, stone, according to the GIA.

When carbon burns in oxygen, that reaction produces carbon dioxide and water. A pure carbon diamond could thus theoretically vanish entirely if burned for long enough; however, most diamonds do have at least some impurities like nitrogen, so the reaction is unlikely to be quite that simple. 

Originally published on Live Science.

Two of the world's most famous diamonds may have originated super deep below Earth's surface, near the planet's core.

All of Earth's natural diamonds first form deep underground from our perspective on the surface. But from the perspective of this planet's great bulk, their usual births occur relatively far from the core. Zest the Earth like a lemon, and you'd uncover diamonds growing at the bottoms of tectonic plates. Those diamonds form about 90 to 125 miles (150 to 200 kilometers) deep, under pressure that exists just where the crust meets the more fluid outer mantle, or middle layer of the planet. No mines reach that far underground, but some of those diamonds do make their way up to where humans can reach them.

The "Hope" diamond, a large and famous stone, as well as the "Cullinan" diamond, the largest rough gemstone ever found, are different. They're "super deep" stones, new research confirms. A 2018 paper showed that these boron-blue gemstones likely originated somewhere in the planet's hot "mantle," a region between the crust and the liquid outer core of the planet, Live Science previously reported This new research shows that, at least sometimes, the stones form deep in this hot zone.

Related: 13 mysterious and cursed gemstones

The research presented today (June 24) at the Goldschmidt geochemistry conference, finds remnants of a mineral called bridgmanite in two less famous diamonds of the same types as the famous gemstones.

All diamonds are crystals made of carbon and various chemical impurities. The type of any specific diamond is determined by the impurities and other conditions present during its creation. So any two diamonds of the same type likely formed in similar conditions.

Bridgmanite is a very common mineral inside Earth, but it doesn't form in the crust or even the upper mantle. 

"What we actually see in the diamonds when they reach [the] surface is not bridgmanite, but the minerals left when it breaks down as the pressure decreases," Evan Smith of the Gemological Institute of America said in a statement. "Finding these minerals trapped in a diamond means that the diamond itself must have crystallized at a depth where bridgmanite exists, very deep within the Earth."

This discovery, the researchers said, suggests both large blue stones originated in the lower mantle, a fluid zone extending from 410 miles (660 km) deep all the way to the planet's liquid outer core.

The first, a 20-carat "type IIb blue diamond" from South Africa, showed evidence of bridgmanite under examination with laser light. The Hope diamond, at 45.52 carats, is a larger example of the same diamond type.

Another diamond, a 124-carat stone about the size of a walnut, is called a "CLIPPIR" diamond (which stands for Cullinan-like, Large, Inclusion-Poor, Pure, Irregular, and Resorbed). It's from Lesotho, a country encircled by South Africa. And, as its type suggests, it is like the 3,106.75-carat Cullinan. Researchers already knew that CLIPPIRs came from very deep below the crust, but this study offers the first direct evidence that they come from the lower mantle.

Neither the Hope nor the Cullinan diamonds were studied as part of this research. But the researchers said that what's true of the less-famous stones is likely true of the more-famous stones as well.

The Cullinan diamond no longer exists in its original large state, having long since been chopped up into smaller stones for sale. The largest two of these is now part of Queen Elizabeth II's "crown jewels."

The massive rough diamond turned up in 1905 just 18 feet (5.5 meters) below the surface at the British-owned Premier Mine in South Africa — a long way from its birthplace in the lower mantle. It was quickly shipped out of the region as part of the British imperial project that exploited and abused Black laborers in order to extract the region's mineral wealth, according to Rapaport, an international corporate network that serves the jewelry market.

The Hope diamond's precise origins are much hazier, but according to the Smithsonian Institution (which now has custody of the diamond), workers at the Kollur mines in India likely discovered the stone before it was sold to the French merchant Jean Baptiste Tavernier in 1668.

Karin Hofmeester, a historian at the International Institute of Social History in Amsterdam, wrote in an essay that men, women and children worked by the 10s of thousands in these dangerous mines at the time for slim wages and food. It's not clear who was responsible for the Hope diamond's discovery or where precisely it turned up.

Researchers do know that when it was found it weighed 122.2-carats, according to the Smithsonian. Once cut to its current state, the Hope passed into the hands of the French royal family, wealthy British collectors, and then American businessmen before ending up at the Smithsonian — a world away from both its lower mantle point of origin and the mine in India where it was discovered.

• The 25 most mysterious archaeological finds on Earth
• The 12 strangest objects in the universe
• 50 interesting facts about planet Earth

Originally published on Live Science.

A piece of a lost continent has been discovered lurking beneath Canada — and the evidence was hiding in rocks that originated in Earth's interior, where diamonds form.

The secret was concealed in a type of diamond-bearing volcanic rock, known as kimberlite. Kimberlite originates deep underground in magma in Earth's mantle, and picks up hitchhiking diamonds as it hurtles toward the surface during volcanic eruptions.  The kimberlite, from Baffin Island in northern Canada, was collected by a diamond mining and manufacturing company. 

Scientists found that the mineral chemistry of the Baffin Island kimberlite matched that from an ancient and long-lost continent that formed nearly 3 billion years ago and broke up 150 million years ago. A portion of that "lost" continent still anchors part of North America, and based on the location of the kimberlite samples, the size of that ancient slab is about 10% bigger than previously thought, researchers reported in a new study.

Related: Shine on: Photos of dazzling mineral specimens

"Finding these 'lost' pieces is like finding a missing piece of a puzzle," lead study author Maya Kopylova, a geologist with the University of British Columbia in Canada,  said in a statement.

Earth's land masses, or continents, didn't always look the way they do now. The first continents emerged when Earth was just a restless baby planet. These ancient and enormous rocky slabs, called cratons, then shattered to form smaller land masses.

"One fragment of the North Atlantic craton is now part of Scotland," Kopylova told Live Science in an email. Another fragment is part of Greenland, and one more is part of Labrador in eastern Canada.

"Now we have found one more fragment on Baffin Island," she said. 

For hundreds of millions of years, plate tectonics pushed continents together to form giant supercontinents, only to pull them apart and push them together again. The last of the supercontinents, Pangaea, began to separate about 200 million years ago, and by around 60 million years ago, the continents had split into the seven that we know today: Africa, Antarctica, Asia, Australia, Europe, North America and South America.

Though the planet's first continents fragmented and were lost to time, remnants of the long-lost land masses survive to this day, as stable cores in our modern continents. The kimberlite samples from Baffin Island, which came from a depth of nearly 250 miles (400 kilometers), bore chemical similarities to mantle rock samples from underneath part of the North Atlantic craton in Greenland, according to the study. 

Under most remnants of ancient continents, the upper mantle contains about 65% olivine — "the main mineral of the upper mantle" — and about 25% of another mineral called orthopyroxene, Kopylova said. By comparison, the mantle makeup under the North Atlantic craton is about 85% olivine and around 10% orthopyroxene. And the mineral ratio in the Baffin Island kimberlite was a close match to the North Atlantic craton, Kopylova said.

Now, scientists know "with certainty" that part of Baffin Island was at some point joined with the North Atlantic craton, "rather than with other ancient continents," according to Kopylova.

This is the deepest location where scientists have found a piece of the North Atlantic craton, greatly expanding their view of the first continents from Earth's distant past, the researchers reported.

"Previous reconstructions of the size and location of Earth’s plates have been based on relatively shallow rock samples in the crust, formed at depths of 1 to 10 kilometers [0.6 to 6 miles]," Kopylova said in the email. With these new findings, "our knowledge is literally and symbolically deeper," she added.

The findings were published online Jan. 7 in the Journal of Petrology.

• 50 interesting facts about planet Earth
• 7 ways the Earth changes in the blink of an eye
• The world’s most famous rocks

Originally published on Live Science.

SAN FRANCISCO — Deep under Earth's surface, earthquakes rumble in the mantle's transition zone, the area that divides the upper mantle from the lower. Liquid in the mantle is thought to play a part in driving those deep earthquakes, but until now, no smoking gun could prove that fluid was present at those depths.

Now, scientists think they may have found evidence of fluid in an unlikely place: inside superdeep diamonds. 

While most diamonds crystallize at depths of 87 to 124 miles (140 to 200 kilometers), superdeep diamonds are found as far as 373 to 497 miles (600 to 800 km) below the surface. Inside these gems forged at depth are tiny flaws, or inclusions, made by fluids. These flaws reveal that liquid is likely flowing in the mantle layers where the diamonds formed.

It's this liquid that interests scientists studying the deep Earth, geochemist Steven Shirey, a senior research scientist at the Carnegie Institution for Science in Washington, D.C., told Live Science at the annual meeting of the American Geophysical Union (AGU). That's because the location and movement of these fluids might be the key to understanding deep earthquakes, Shirey said.

Related: Shine On: Photos of Dazzling Mineral Specimens

In new research, presented at the AGU meeting on Tuesday (Dec. 10), Shirey and his colleagues modeled the movement of fluid at depth using information about the spots where these diamonds formed in the mantle. 

In creating these models, the scientists are hoping to connect the dots among fluid movement into the deep mantle, diamond formation "and the physical rupture properties of the rocks in that region" of the mantle-transition zone, Shirey said. As a next step, researchers need to "relate the currents of those fluids to deep-focus earthquakes," he explained.

Deep earthquakes are energetic, frequent and "a very interesting manifestation of plate tectonics — kind of as deep as we can see plate tectonics," Shirey said. 

Just what happens at that frontier of plate tectonics "turns out to be a very interesting planetary question," he said.

• Sinister Sparkle Gallery: 13 Mysterious & Cursed Gemstones
• 50 Interesting Facts About Planet Earth
• 7 Ways the Earth Changes in the Blink of an Eye

Originally published on Live Science.

It was a gem of a find. A diamond that was recently extracted from a mine in Yakutia, Russia, had a surprise lurking inside: a tiny, second diamond. 

The outer diamond measured about 0.2 inches (4.8 millimeters) long, while the wee stowaway spanned about 0.08 inches (2 mm) long and weighed about 0.0001 ounces (0.004 grams). The hidden gem rattled around inside an air pocket at the heart of the larger stone, and Russian experts who examined the peculiar double gem declared it the only known example of a diamond with another diamond inside it, according to a statement.

This unusual diamond-in-a-diamond drew comparisons to a traditional Russian toy called a matryoshka doll, in which successively smaller wooden dolls are nested inside bigger dolls, representatives with the Russian diamond mining company Alrosa told Live Science in an email.

Related: Photos: The World's 6 Most Famous Rocks 

Workers detected the oddball gem while sorting diamonds in Alrosa's Yakutsk Diamond Trade Enterprise in Yakutia, Alrosa representatives said. 

"At first, the crystal did not appear to be any different from other crystals, but when examining it in detail, the sorter noticed movement inside," they said. (Diamonds are composed of carbon atoms arranged in a certain crystalline structure.)

The sorter photographed the crystal and delivered it to Alrosa's Research and Development Geological Division, "which has a laboratory and analytical base that allows the research of diamonds through non-destructive physical methods," according to the email.

Indirect analysis of the nitrogen content in the gem told the scientists that the diamond was about 800 million years old. These precious stones originate as humble graphite — a form of carbon — before the intense pressure deep in Earth's mantle transforms them into diamond crystals. 

But for a diamond to naturally form inside another diamond isn't just rare — it's unheard of, said geologist George Harlow, a curator in the Department of Earth and Planetary Sciences at the American Museum of Natural History in New York City.

"I have no knowledge of anything like this in the natural mineral world," he told Live Science in an email. (Harlow was not involved in the analysis of the double diamond).

Crystals and grit

So, how did this Russian diamond retain an air pocket at its core with another gem inside?

The internal diamond likely grew first, and then the diamond shell took shape around it, according to Alrosa representatives. One possible explanation is that the diamond core grew so quickly that a layer of porous diamond grit — polycrystalline diamond substance, rather than fully formed crystals — coated the diamond core. Another layer of diamond crystals then began to form on top of the polycrystalline grit. But, as the little diamond was squeezed and heated in Earth's roiling mantle, the gritty layer dissolved and left behind a diamond nugget inside a diamond shell.

There was enough space left around the smaller diamond that it was able to move freely inside the bigger one, "like a matryoshka nesting doll," Alrosa representatives said in the email.

Diamonds fascinate humanity with their beauty, but some notable examples, though beautiful, are thought to be cursed. Among the most famous of these allegedly cursed jewels is the Hope Diamond, which had a long history of owners plagued by lost fortunes, personal tragedy, insanity and violent deaths.

These spectacular gems also hold intriguing secrets about our planet. A diamond that was recently discovered in South Africa held a mineral that was previously unknown to science. Some diamonds contain traces of salt from ancient oceans. And tiny mineral flaws in diamonds can reveal snapshots of Earth's continents as they took shape 2.5 billion years ago, Live Science previously reported.   

Perhaps there’s another story to be told by this newfound gem-inside-a-gem.

• Photos: The World's Weirdest Geological Formations 
• Photos: Rare Diamonds Make US Debut at LA Natural History Museum
• Photos Dazzling Minerals and Gems

Originally published on Live Science.

Tiny flaws in diamonds hold the secret to the formation of the first continents.

In a new study, researchers used inclusions — imperfections derided by jewelers but valuable to scientists — to trace diamond formation. They found that the sulfide minerals inside the inclusions were last at the surface of the planet 2.5 billion years ago, before the rise of oxygen in the atmosphere.

The findings reveal the history of the continents and mantle where the diamonds form, said study leader Karen Smit, a research scientist at the nonprofit Gemological Institute of America. The diamonds in the study, found in West Africa, indicate that the ancient continents in that region formed by subduction, a process in which one slab of crust pushes under another. [Photos: Rare Diamonds Make US Debut at LA Natural History Museum]

"We can track through 2.5 billion years of Earth history just through this one sulfide inclusion," Smit told Live Science.

Inside a diamond

Diamonds form deep in the mantle. Most, Smit said, form around 125 miles (200 kilometers) deep, and some form even deeper, around 250 to 435 miles down (400 to 700 km). The deepest hole ever drilled, the Kola Superdeep Borehole in Russia, only penetrated 7.6 miles (12 km). Diamonds are then brought to the surface fairly rapidly via deep volcanic eruptions.

Smit and her colleagues were studying the nitrogen in diamonds from the Zimmi region of Sierra Leone when they noticed that speck-size inclusions of sulfides in the diamonds showed signs of having existed in the mantle before the diamonds formed, meaning they were trapped within the crystallizing diamonds and carried up to the surface with them. They began investigating the isotopes of sulfur within the inclusions. Isotopes are variations of atoms with differing numbers of neutrons in their nuclei.

What they found revealed that the inclusions were very old indeed. Oxygen shields the sulfur from certain reactions with ultraviolet light, so researchers can tell whether sulfur formed in an oxygen-rich or low-oxygen environment. These isotopes formed in the atmosphere before there was much oxygen in the atmosphere, around 2.5 billion years ago, Smit said. The diamonds themselves are much younger than that, and formed around 650 million years ago.

A history of continents

The researchers then examined similar inclusions in diamonds from Canada's Ekati mine. These inclusions are 3.5 billion years old and do not have the same isotope signals as the West African diamonds. The contrast tells a story about how the continents formed, Smit said. Early on, continents probably formed from melting mantle that oozed upward in the form of basalt, similar to how Iceland or Hawaii form today. The minerals in this crust formed in the mantle, not in contact with the atmosphere.

Later in Earth history, though, subduction became important for forming stable continents. One chunk of crust would grind under another; denser material would sink and less-dense material would rise to form continental crust. This is how the sulfur in the West African diamonds would have gotten deep beneath the surface, Smit said.

The most stable, long-lasting crust is attached to portions of the mantle called "keels," so named because they stabilize crust just as a keel stabilizes a ship. More studies of inclusion-rich diamonds could help explain how and why these keels form, Smit said. So far, there are only four locations around the world, including West Africa and Canada, with diamonds that contain both sulfide inclusions and minerals used to date the diamonds' formation. More locations would help trace Earth's history in more detail, Smit said, but these studies are challenging because the diamonds are destroyed in the process of analysis.

"We need diamonds," Smit said, "to destroy for science."

• Photos: The World's Weirdest Geological Formations
• Spectacular Geology: Amazing Photos of the American Southwest
• In Photos: The UK's Geologic Wonders

Originally published on Live Science.

An Enchanted World

Our world is enchanted — and if you need proof, just turn to science. We've collected 10 of our favorite awe-inspiring science stories to remind you just how amazing the world really is. From the 1.5 million penguins that we didn't know existed until recently to the mysterious "sky glow" named "Steve." From the microbes that can't live without light but thrive in complete darkness deep in the water to the massive throne of diamonds that shimmer from hundreds of miles below us.

The world is amazing, see for yourself.

Steve, the non-aurora

Meet Steve, the non-aurora. For decades, a ribbon of purple light danced across Northern Canada's skies. But though the glowing phenomenon was a familiar sight to locals, skywatchers didn't actually give it a name until 2016, when they named it…"Steve."

Weirder still, it wasn't until this year that scientists figured out what Steve was — or in this case, wasn't. Namely: Steve is not an aurora, according to a paper published in August in the journal Geophysical Research Letters. Steve is slimmer and longer in the sky, and perhaps more important, while auroras are made up of characteristic charged particles in the Earth's atmosphere… Steve isn't.

So, what's a scientist to do? Keep studying. And also, keep the name — the phenomenon, now dubbed a "sky glow," still goes by Steve, or "Strong Thermal Emission Velocity Enhancement." [Read more about STEVE]

Penguins of Danger Islands

Sometimes we miss one or two things, sometimes we miss millions. In this case, we're talking penguins.

This year, scientists found about 1.5 million Adélie penguins waddling around on the rocks of Antarctica's Danger Islands. The elusive penguins' location was given away by their poop: Scientists became aware of the large population of penguins in the area after spotting penguin poop stains on the ice in NASA satellite images. Motivated by their finding, the scientists embarked on an expedition to the Danger Islands in 2015, where, sure enough, they happened upon a great number of the birds. According to a study published in March in the journal Scientific Reports, the researchers set about tallying the penguins using a mix of hand counting, drone footage and a neural-net-counting program. They estimate that more than 1.5 million penguins — a "supercolony" — live on the rocks. The discovery came both as a surprise and a delight, as populations of Adélie penguins in other parts of Antarctica have been declining for the past 40 years under pressure from climate change.

Those penguins have lived on the islands, undetected, for at least 2,800 years, according to new unpublished research revealed at the American Geophysical Union meeting in Washington, D.C. on Dec. 11. Though their numbers are in the millions, these inhabitants may also be on the decline, the researchers said. [Read more about the penguins]

An impossible Particle

Physics tries to make sense of the world — sometimes the world laughs back. This year, scientists came up with the strongest-ever evidence that sterile neutrinos, particles that can make their way through matter without so much as an interaction, exist. The existence of sterile neutrinos was first suggested in the 1990s, when a neutrino detector in New Mexico, reported more neutrinos than the Standard Model of physics could explain. (The Standard Model of physics is how we currently define the universe and everything in it.) Since then, however, all other experiments, done in various laboratories across the world, couldn't find any evidence of this elusive particle.

Until this year, when an experiment at the Fermi National Accelerator Laboratory near Chicago detected more neutrino particles than should exist.

So, does it exist? Well…we don't know. But if it does, scientists are going to have to redefine the universe. [Read more about this elusive particle]

A quadrillion ton of diamonds

Ninety to 150 miles beneath Earth's surface, there may exist a treasure trove of diamonds — a quadrillion tons of the glittering gems, in fact, or about a thousand times more than was previously thought. Scientists can't actually see these diamonds, but they think they exist because of how seismic waves — the vibrations from earthquakes and tsunamis — behave when they hit different rocks below the surface. But because researchers can't actually access these diamonds through the layers of earth to study them, they instead used computers and created "virtual rocks" that each contained a different ratio of different kinds of material, including diamond. Then, the scientists compared how fast seismic waves would travel through these imaginary composites with how fast they travel through the rocks of the underworld, and found the best matches with those rocks containing diamonds. [Read more about the endless diamonds]

Mysterious new DNA

The recipe that crafts a life and gives it a spice of personality is, for the most part, folded into a twisted ladder form known as the double-helix. But DNA doesn't always assume this well-known form. Scientists learned this year, for example, that sometimes our genetic code can fold into less common forms. One of these rarer structures is a four-stranded knot called an "i-motif." However, whether this structure could actually be found in human bodies has been controversial, because i-motifs love acidic environments, way more than what was thought our cells could provide.

But a study published this year in the journal Nature Chemistry provided the first direct evidence that this weird knot of DNA can, and probably does, exist in the human body. What's more, it's likely found in every one of our cells.

In ab dishes, scientists used antibodies to find and bind to these knots of DNA in human cells, and light up when they found one. But when the team looked at the antibodies, they were surprised to see them twinkling on and off, meaning that the DNA was continuously folding into i-motifs and then unfolding. Though researchers don't know why these weird knots exist, they mostly folded into existence during transcription — when DNA is translated into RNA — so they think the i-motifs have something to do with the process of expressing genes. [Read more about i-motifs]

Microbes in the dark

Deep beneath the Earth's surface, where sunlight doesn't penetrate, live some microbes that were thought to be dependent on sunlight to survive. Yet somehow, in this darkness, they're thriving.

The microbes in question, called cyanobacteria, have been around for billions of years, and were key players in creating the oxygen-rich environment necessary to kick-start all forms of life. But the way they did that — and the way most most cyanobacteria function nowadays — is by creating energy through photosynthesis, a process that uses sunlight to to turn carbon dioxide into food, releasing oxygen along the way.

Cyanobacteria are therefore typically found in places with at least some sunlight. But this year's discovery of cyanobacteria in the so-called dark biosphere, 2,011 feet (613 meters) below the water's surface where sunlight is scarce, if not nonexistent, challenged this notion. Scientists suggested that these microbes didn't use photosynthesis but rather survived by absorbing hydrogen gas, combining that with oxygen in their bodies, then releasing hydrogen electrons back into the dark waters: the first evidence that cyanobacteria can adapt to and thrive in a dark world. [Read more about these microbes]

Underwater highway

Deep in the Tasman Sea, east of the island of Tasmania, there's a hidden highway brimming with sea life. This year, while on an expedition to study phytoplankton and its ability to sustain life in ocean ecosystems, researchers discovered a chain of underwater volcanoes 3 miles below the surface of the water. These volcanoes likely formed thousands of years ago and were made up of both low plateaus and high peaks — a unique signature that today may serve as "signposts" for migrating whales. And indeed, while the scientists were surveying the seamounts, they were greeted by dozens of curious humpback and long-finned pilot whales, navigating the underwater world. The submerged mountain range contained more than migrating whales; according to the researchers, it was also teeming with phytoplankton and above it flew many different kinds of seabirds, making it"undoubtedly" a biological hotspot. [Read more about this underwater highway]

Hidden civilization

Buried deep beneath a Guatemalan jungle lies the remains of an ancient Mayan civilization. Researchers spotted these remains using "light detection and ranging," or "lidar," technology that maps out features on the Earth's surface. This technology can help distinguish between natural and man-made structures and even between different kinds of man-made structures. The traces of ancient life hidden below the trees was both urban and rural, consisting of farmland, houses, palaces, ceremonial centers, roads, irrigation canals, reservoirs and pyramids. The lidar images revealed that much of it was heavily modified for farming with 368 square miles (952 square km) of farmland and 140 square miles (362 square km) of terraces and other altered agricultural land. All this modified land was needed, they said, to sustain up to 11 million people that likely lived there from A.D. 650 to 800. [Read more about this hidden civilization]

Largest wave

A video straight out of a nightmare — or, if you're a surfer, a dream — circulated around Twitter back in August. It shows a gigantic wall of water, and a tiny dot of a person riding it toward its breaking point. This wave, which rose 80 feet (24 meters) above the water's surface off the coast of Nazaré, Portugal, is thought to be the largest ever surfed by a person. The brave soul that broke the world record was a Brazilian surfer named Rodrigo Koxa. The tall wave that helped him was a result of "amplifying" features of the Nazaré shoreline — an upward sloping underwater terrain as you approach the shore and an underwater canyon with high walls that sits about 16,000 feet (nearly 4,900 m) below the ocean's surface. This brave feat actually happened in 2017, but a video of it went viral on Twitter on this year. [Read more about this wave]

Frozen worms

During the Pleistocene, some soil-dwelling microscopic worms froze when the temperature got cold. Then, 42,000 years later, in 2018, they thawed, woke up, and began to eat. (We don't blame them.) The worms were found in samples of Siberian permafrost that very precisely preserved these tiny, 1 millimeter multicellular animals. When scientists defrosted the samples, he microscopic creatures began wriggling around and eating. This is the first time that multicellular animals were naturally cryopreserved, but not the first time that any (potentially?) living entity was. Another group of scientists had previously found a giant virus — which affects only amoebas — that was defrosted after a 30,000-year slumber, again in Siberian permafrost. (We can get into whether viruses are alive another time.) [Read more about these frozen worms]

Miners discovered a 552-carat yellow diamond in the Diavik Diamond Mine in the Northwest Territories this October, Dominion Diamond Mines announced last week. For Canada, that's a big rock: The country's previous size record for a diamond was 187.7 carats. However, for the world, the largest diamond ever found is the Cullinan Diamond, discovered in South Africa in 1905. That rock clocks in at 3,106.75 carats.

For another comparison, the famous Hope Diamond, held at the Smithsonian Institution in Washington, D.C., is 45 carats. It’s famous both for its rare blue color and its alleged habit of bringing misfortune to those who possess it. [Sinister Sparkle Gallery: 13 Mysterious & Cursed Gemstones]

Diamonds typically come from carbon trapped deep in Earth's mantle. Under superhigh heat and pressure, this carbon crystallizes into a shiny, much-coveted gemstone. Deep volcanic eruptions bring the diamonds close to the surface. (Diamonds can form in other ways, such as in large asteroid impacts at the surface, but commercial diamonds typically come from the mantle.)

The Canadian record-breaker is a yellow diamond, which gets its color from nitrogen impurities within the crystal. Yellow diamonds are rarer than white diamonds but were still largely considered a cheaper stone until recent years. According to a 2012 Wall Street Journal article, yellow diamonds began to gain in popularity (and price) around 2010, a trend driven by the high cost of colorless diamonds and the choice by several celebrities to use yellow stones for their own jewelry.

The mine where the stone was found sits 137 miles (220 kilometers) from the Arctic Circle, on an island in a lake called Lac de Gras, where a series of deposits of an igneous rock called kimberlite are studded with diamonds. According to GIA, a nonprofit that evaluates diamond quality, the Diavik mine has produced more than 100 million carats of diamonds since it opened in 2003.

The biggest diamonds on record, however, come from South Africa. The Cullinan was a near-colorless stone that, once cut, yielded two major Crown Jewels of the United Kingdom: the Great Star of Africa (530.4 carats) and the Second Star of Africa (317.4 carats). The former graces the top of a scepter and the latter a crown.

Just this year, the Letšeng mine in Lesotho coughed up a 910-carat colorless diamond, the fifth largest ever found.

It's not entirely clear why South Africa's mines often contain giant gems. However, some research suggests that the biggest diamonds form differently than smaller stones do. One 2016 study found that the composition of giant diamonds differs from that of smaller diamonds. The larger ones tend to have irregular crystalline structures and few inclusions, or nondiamond material, the research found. However, these bigger stones did contain tiny metallic grains not seen in smaller diamonds, suggesting that the big ones may form in small metallic pockets very deep in the mantle.

• The 7 Strangest Asteroids: Weird Space Rocks in Our Solar System
• Photos: Dazzling Minerals and Gems
• Shine On: Photos of Dazzling Mineral Specimens

Editor's Note: This article was updated to indicate that the Letšeng mine is in Lesotho, not in South Africa as had been previously reported.

Originally published on Live Science.

That special mineral that humans use to profess their love for one another? It might not be so special. A new study suggests that Earth's interior is filled with a quadrillion tons of diamonds.

A new study published in June in the journal Geochemistry, Geophysics, Geosystems suggests that there are 1,000 times more diamonds below the surface of the Earth than was previously thought.

But these diamonds are unreachable: They're located about 90 to 150 miles (145 to 240 kilometers) below the surface of the Earth in the "roots" of cratons, which are large sections of rock. Cratons lie beneath most continental tectonic plates and have barely moved since ancient times, according to a statement from MIT News. [Photos: The World's Weirdest Geological Formations]

A group of researchers from various universities around the world discovered the glitzy stash by looking at seismic waves beneath the Earth. Because these vibrations can change, based on the composition, temperature and density of various rocks that it hits, researchers can use these recordings to construct an image of the unreachable interior of the Earth.

They found that the underground vibrations, produced from natural processes such as earthquakes and tsunamis, tended to speed up when passing through cratonic roots; the speedup was greater than would be expected from the fact that cratons tend to be colder and less dense than surrounding structures (both of which are conditions that would speed up the waves).

Using records of seismic activity that were kept by government agencies such as the U.S. Geological Survey, the team created a three-dimensional model of the velocities of seismic waves that traveled through the planet's major cratons. Then, they created "virtual rocks" from various combinations of different minerals and calculated how fast seismic waves would travel through those rock compositions.

They found that the best explanation for the speeds actually observed underground versus those predicted in their virtual rock models was that 1 to 2 percent of the roots of the cratons was made up of diamonds, while the rest was made up of peridotite (the main type of rock in Earth's upper mantle) and a little bit of eclogite rocks (from the ocean's crust).

When "waves pass through the Earth, diamonds will transmit them faster than other rocks or minerals that are less stiff," said Joshua Garber, a postdoctoral student at UC Santa Barbara and lead author of the study.

Though "we found that much of the data were best explained by diamond … we cannot say for certain," Garber said. Since it's difficult to directly sample these regions (but not impossible, since sometimes parts of these cratonic roots are brought to the surface from erupting magma), this is the best explanation right now, Garber said.

But other researchers have suggested some alternative explanations: Perhaps, these cratonic rocks are cooler than what the literature suggests, which means the rock will be stiffer — and thus, seismic waves will travel more quickly through them — even without the diamond or eclogite rocks, Garber added. However, based on their data, he thinks this latter scenario is less likely.

"Our understanding of the deep Earth continues to improve as we make more measurements, do more experiments and occasionally get samples," Garber said. "I suspect we will continue to be surprised by what we find."

Originally published on Live Science.

Huge clouds of tiny, glowing diamonds are floating through empty regions of the Milky Way, and astronomers had no idea the little shimmering particles were there. The discovery could help researchers figure out what happened in the first moments after the Big Bang.

That's because these diamonds have turned out to be the culprit behind a mysterious phenomenon scientists have termed "anomalous microwave emissions" (AMEs). The galaxy is full of strange, gentle microwave beams, but until recently, scientists had no idea where they came from.

The most common theory was a group of organic molecules called polycyclic aromatic hydrocarbons (PAHs). But in a new paper published today (June 11) in the journal Nature Astronomy, a team of scientists from England, the United States and Germany proved the PAH theory wrong. The AMEs, they showed, come from spinning nanodiamonds. [Top 10 Unexplained Phenomena]

Part of the reason AMEs were such a mystery is that, for a long time, researchers hadn't been able to track them down to any precise points of origin in space, the researchers explained in a statement. AMEs were just these faint, sourceless puffs of microwave energy that appeared out of the darkness. Scientists suspected that PAHs, which are spread throughout interstellar space and do emit faint infrared radiation, might be the cause. But without a specific point of origin to study, they couldn't be sure.

Recent research also cast doubt on the PAH hypothesis. Most notably, a 2016 paper in The Astrophysical Journal showed that AMEs don't pulse and fluctuate in the same way as the infrared beams from PAHs do, suggesting they might not be linked after all.

Using the Green Bank Telescope in West Virginia and the Australia Telescope Compact Array, the new study's researchers found three clouds of dirt and dust around newborn stars (the sorts of clouds that eventually coalesce into planets and asteroids) that were emitting AMEs. But those clouds didn't contain the faint infrared signature of PAHs. However, they did contain the signatures of spinning nanodiamonds.

The researchers created computer models of the diamonds and found that hot, spinning nanodiamonds, each just 0.75 to 1.1 nanometers across (less than half the width of a strand of DNA, or about 0.00000004 inches), could produce the AMEs they recorded.

Narrowing down the source of the AMEs is a big deal, they said, because microwaves in outer space hold so much information about the ancient universe. The fingerprints of the Big Bang are still visible in outer space in what's known as the cosmic microwave background (CMB). But more recent sources of microwaves, like AMEs, mess up that picture.

The more scientists know about where microwaves in space come from, the more precise a picture they can build of the CMB. And a more precise picture of the CMB can tell scientists a lot about the first moments of the universe.

Originally published on Live Science.

An asteroid that slammed into the Sudan desert on Oct. 7, 2008, shot out lots of little space rocks holding a precious secret: diamonds that likely formed billions of years ago inside the embryo of a now-decimated planet.

That lost planet was the size of Mercury or perhaps Mars, researchers now say.

In the space rocks, which are also called meteorites, researchers found compounds common to diamonds on Earth, such as chromite, phosphate and iron-nickel sulfides. It's the first time these diamond components have been found in an extraterrestrial body, the researchers said in a new study describing the findings. [See Photos of Meteorites Discovered Around the World]

The finding provides more information on the early days of our solar system about 4.4 billion years ago, when the zone near the sun had several planetary embryos. Many of them coalesced into the planets we see today. Others fell into the sun or were ejected into interstellar space.

The meteorites were formed after an asteroid slammed into Earth's atmosphere — making it technically a meteor — exploding 23 miles (37 kilometers) above the Nubian Desert in Sudan. The explosion from the 13-foot-wide (4 meters) body shot fragments all over the desert below. Researchers picked up 50 of these pieces, which ranged in size from 0.4 to 4 inches (1 to 10 centimeters).

(An asteroid is a space rock, a meteor is a space rock burning up in Earth's atmosphere, and a meteorite is the leftover fragment that reaches Earth after a meteor comes through the atmosphere.)

Researchers collected these tiny meteorites into a collection called "Almahata Sitta"; this is the Arabic word for "Station Six," a train station nearby the meteorite fall and between Wadi Halfa and Khartoum. After collecting the tiny meteorites, researchers discovered nano-size diamonds inside them. But at first, the origins of the diamonds eluded researchers.

Nanodiamonds can form from "normal" static pressure inside a large parent body like Earth, but there are other origin theories as well. High-energy collisions between worlds in space can leave such diamonds behind, as can deposition by chemical vapor,according to a statement from the Federal Polytechnic School of Lausanne in Switzerland.

The new study, however, revealed that the diamonds in the meteorite could form only under pressures higher than 20 gigapascals. This is an extremely high form of pressure that humans can generate with certain explosives.

"This level of internal pressure can only be explained if the planetary parent body was a Mercury- to Mars-sized planetary 'embryo,' depending on the layer in which the diamonds were formed," the researchers said in a statement from the Federal Polytechnic School of Lausanne in Switzerland. Farhang Nabiei, a doctoral student at the institution, led the research.

That planetary embryo would have then been destroyed through violent collisions, the researchers noted.

The research was published online yesterday (April 17) in the journal Nature Communications.

Originally published on Live Science.

It sounds like the start of a James Bond feature: A 910-carat diamond has been discovered in a mine in the African country of Lesotho. The find is the fifth-largest gem-quality diamond ever discovered.

Gem Diamonds Limited, a mining company that operates in Lesotho and Botswana, announced the find yesterday (Jan. 15). It's the largest diamond ever found in the country's Letšeng mine, which has a reputation for turning up monster rocks. In 2006, a 603-carat diamond dubbed the "Lesotho Promise" was found at the same mine.

A 910-carat diamond weighs 6.4 ounces (182 grams), said Philipp Heck, a curator in the Earth sciences section of Chicago's Field Museum of Natural History who was not involved in the gem's discovery.

"It's definitely a big deal," Heck wrote in an email to Live Science. "This is a very large and rare diamond." [Sinister Sparkle Gallery: 13 Mysterious & Cursed Gemstones]

Making the find even more exciting is that it is of a quality coveted by jewelers and jewelry-lovers. The diamond is a Type IIa diamond, a category of diamond very low in nitrogen: For every million carbon atoms in a Type IIa stone, there are fewer than 10 nitrogen atoms, Heck said. Nitrogen lends diamonds a yellow hue, so the low concentrations of the element in the new Lesotho find mean the diamond is quite colorless.

Letšeng mine has a high concentration of diamonds, Heck said, but most are small. The sheer number, though, means that a few giants lurk in the mine, too.

Diamonds are formed about 125 miles (200 kilometers) below the surface of the Earth, where pressure and heat squeeze carbon molecules into a very strong crystalline structure. This requires temperatures of around 2,200 degrees Fahrenheit (1,200 degrees Celsius) and pressures upward of 725,000 pounds per square inch. To remain diamonds, these crystals must be brought to the shallow surface within a matter of hours by deep volcanic eruptions, allowing the objects to cool rapidly, locking their crystalline structure in place.

The monster rock from Letšeng is still raw and uncut, but will likely be faceted and polished to give it the sparkle that diamond buyers love so much, Heck said. Diamonds as large as the newly discovered stone rarely get divided into smaller stones and sold at places like Zales, he said; they're more likely to be kept ridiculously giant and sold at auction to well-heeled bidders.

Don't worry too much about that Bond plot, though. Diamonds are used in the internal workings of lasers, but a dastardly villain would have better luck using a synthetic diamond in a world-destroying weapon, Heck said.

"Even this new, big and clear Lesotho diamond is probably less pure and therefore less suitable for a laser than a synthetic diamond," he said.

Original article on Live Science. 

The world's largest, most valuable diamonds may be born in pockets of liquid metal located deep within the Earth, a new study finds.

This discovery suggests that pockets of liquid metal peppered throughout Earth's mantle layer, between the planet's crust and core, may play a key role in how carbon and other elements key to life cycle between the Earth's interior and the planet's surface, the researchers said.

In general, diamonds form deep in the hot rock of Earth's mantle, rising to the surface with volcanic eruptions. The biggest gem-quality diamond found to date is the Cullinan diamond, which was unearthed in South Africa in 1905. The 3,106.75-carat diamond, which was later cut up into several polished pieces, originally weighed 1.37 lbs. (621.35 grams), and was about 3.86 inches (9.8 centimeters) long. [Sinister Sparkle Gallery: 13 Mysterious & Cursed Gemstones]

Previous research found that the world's largest gem-quality diamonds stand out from smaller jewels not just in size, but also in composition and structure.

"They have very few inclusions trapped inside them — that is, material that isn't diamond," said study lead author Evan Smith, a geologist at the Gemological Institute of America in New York. "They are also relatively pure, which means most of these diamonds are made just of carbon atoms, unlike a lot of other diamonds, which contain nitrogen atoms here and there substituting for their carbon atoms."

In addition, when the biggest diamonds are in their rough, unpolished state, "they're irregular in shape, like a lollipop that's been in someone's mouth for a while, instead of the nice, symmetrical crystals one often thinks of with diamonds," Smith told Live Science.

These differences led scientists to speculate that large diamonds might form in different ways from smaller, more common diamonds. However, the world's biggest gem-quality diamonds "are worth so much money that it's very difficult to get access to them for research," Smith said. This has stymied studies that might solve the mystery of these large gems' origins, he explained.

Now, Smith and his colleagues have analyzed 42 finished specimens of such jewels that were each loaned to the researchers for a few hours at a time. In addition, the scientists examined two unfinished samples and nine so-called "offcuts," the pieces left over after a jewel's facets are cut and polished for maximum sparkle.

The researchers detected tiny metallic grains trapped inside these samples. The inclusions consisted of solidified mixtures of iron, nickel, carbon and sulfur, a combination never seen in common diamonds, said study co-author Steven Shirey, a geochemist at the Carnegie Institution for Science in Washington, D.C. The scientists also detected traces of methane and hydrogen in the thin spaces between these inclusions and the encasing diamond.

The metallic grains are evidence that massive diamonds likely have unusual origins, the researchers said. The chemistry of these metal inclusions suggests that large diamonds crystallize from pockets of metallic liquid. In contrast, other diamonds likely grow from a chemical soup loaded with carbon, oxygen and hydrogen, Smith said.

A number of the samples the researchers examined also possessed silicon-bearing mineral inclusions that form at the high pressures found at extreme depths, the scientists said. Researchers estimated that large diamonds are "superdeep" gems that likely form at depths of about 254 to 410 miles (410 to 660 kilometers). In comparison, previous research suggested that most other gem diamonds form at depths of just 93 to 124 miles (150 to 200 km).

These findings provide direct evidence of long-suspected, theoretically predicted chemical reactions in Earth's mantle that create pockets of metallic iron-nickel alloy, Smith said. Most of the iron and nickel in Earth's mantle, in contrast, is usually bound to oxygen or another chemical, he explained.

Although large diamonds and more common diamonds are sometimes found together, that does not mean they formed together, Shirey told Live Science. Instead, the same magma that flows upward to bring large diamonds to the surface can also drag up smaller diamonds that formed at shallower depths, he said.

These findings should not be taken to suggest "that there is an ocean of liquid metal deep in the Earth's mantle," Smith said. The liquid metal likely comes only in pockets "limited to perhaps fist-sized, if I were to guess, that are peppered throughout the mantle," he added.

"There's not a lot of this metallic iron — just about 1 percent or so of the mantle," Smith said. "Still, it changes the way we have to think about the deeper Earth, because elements like carbon dissolve well in metallic iron. This means the presence of this metal can impact the cycling of carbon, nitrogen and hydrogen from the deep Earth to the surface, from the Earth's mantle to where we live."

Future research could investigate what other elements are in these large diamonds or their offcuts, and what isotopes are included, Smith said.

"That might help shed light on the origin of this metal. Where does it come from, how does it form, what lifetime does it have, what processes does it participate in," he said.

The scientists detailed their findings online today (Dec. 15) in the journal Science.

Original article on Live Science.

Diamond debut

Rare and colorful gems, including an extremely rare pink diamond and the stunning Argyle Violet Diamond, are making their U.S. debut at the Natural History Museum of Los Angeles County from Dec. 16, 2016, through March 19, 2017. The exhibition, called "Diamonds: Rare Brilliance," can be seen in the museum's Gem and Mineral Hall. It will teach viewers about the rare properties of colored gemstones, the science behind natural colored diamonds and how light and chemistry give diamonds color.

Pretty in pink

A fancy intense pink diamond, the Juliet Pink is more than 30 carats. This beauty is exceptionally rare due to its intense color, size and lack of inclusions.

Fantastic accessory

Totaling 98.70 carats, the Juliet Pink Diamond is set in a necklace with marquise-, pear- and round-cut white diamonds.

Very violet

Rare among rare diamonds, the Argyle Violet is unbelievably large — 2.83 carats — for a diamond of this type.

Unique look

The Argyle Violet Diamond has a never-before-seen combination of color, clarity and size.

Deep color

The Argyle Violet Diamond is like no other known diamond and is the largest found in Western Australia.

Record-setting glitter

Known as the Argyle Violet Diamond, it is the largest specimen of a violet diamond to be unearthed at the Argyle Diamond Mine.

Making a statement

Surrounded by pink diamonds in a ring setting, the Argyle Violet awaits exhibition.

Abundant colors

At almost 36 carats, close to 88 colored diamonds — brilliant white, blaze-cut white and natural multicolored diamonds — handily show off the natural fluorescent properties of the stones in the Rainbow Diamond Necklace.

Regal elegance

Using a 1.63-carat Fancy Purple Vivid diamond encompassed by white diamonds, jewelers created the Victorian Orchid Ring.

Showcase for jewels

The Otis Booth Pavilion offers an inviting entrance to the Natural History Museum of Los Angeles County, which opened its Gem and Mineral Hall in 1978.

Gems galore

The Gem and Mineral Hall of the Natural History Museum of Los Angeles County is famous around the world, offering a 6,000-square-foot permanent set of exhibition halls.

Exhibits of rarities

The Natural History Museum of Los Angeles County's Gem and Mineral Hall displays more than 2,000 specimens in two giant galleries. The entire collection of gems consists of upward of 150,000 items and is the largest in the western United States.

Diamonds may decorate some of the most coveted pieces of bling, but these precious stones could have more practical (though admittedly less sparkly) uses one day: The jewels could be used as a way to store vast amounts of data using atom-size flaws ordered in 3D arrays, according to a new study.

For decades, artificially grown diamonds, which are as hard as their gem-quality counterparts, have been used in industrial drills and saws and in durable coatings for biomedical implants. [Sinister Sparkle Gallery: 13 Mysterious & Cursed Gemstones]

Recently, scientists have explored creating defects in diamonds for potential use in quantum computers. Previous research suggests such machines could carry out more calculations in an instant than there are atoms in the universe.

Now, in a new study, scientists said these defects in diamonds could help store information, much like how microscopic pits in CDs and DVDs help encode bits of data.

"We are the first group to demonstrate the possibility of using diamond as a platform for the superdense memory storage," said study lead author Siddharth Dhomkar, a physicist at the City College of New York.

The researchers experimented with diamonds whose crystals contained a number of holes where carbon atoms should be. These imperfections are known as nitrogen vacancy centers, because nitrogen atoms are located near the holes, or vacancies.

The defects usually held electrons instead of carbon atoms, giving the features a negative electrical charge. However, the researchers could give these defects a neutral charge by shining lasers on them. The change from negative to neutral altered how the defects behaved after they absorbed light: They went from fluorescing brightly to staying dark, the researchers said. This change is reversible, long-lasting and not disrupted by weak levels of illumination, the researchers added.

The findings suggest that diamonds could encode data in the form of negatively and neutrally charged defects, which lasers can read, write, erase and rewrite, the scientists said.

In principle, Dhomkar said, each bit of data could be stored in a spot on the diamond only a few nanometers, or billionths of a meter, wide. This is much smaller than any similar features used in data storage, and could give rise to superdense computer memories, he said.

However, the researchers currently have no way to read or write data encoded using such tiny features. As such, "the smallest bit size that we have achieved is comparable to a state-of-the-art DVD," Dhomkar told Live Science.

The researchers did show they could encode data in 3D — that is, as stacks of 2D images.

"One can enhance storage capacity dramatically by utilizing the third dimension," Dhomkar said. The researchers' 3D data-storage technique could lead to a diamond-based storage disk that can store 100 times more data than a typical DVD, Dhomkar said.

In the future, Dhomkar and his colleagues will explore ways to read and write data from nano-size bits on diamond crystals, he said. "The storage density of such an optimized diamond chip would then be far greater than [that of] a conventional hard disk drive," he said. 

The scientists detailed their findings online today (Oct. 26) in the journal Science Advances.

Original article on Live Science.

Earth has gotten a number of face-lifts over its 4.4-billion-year history, but in one respect, the planet may look the same way it did when it was young, new research shows.

Primeval diamonds from Witwatersrand, South Africa, contain evidence that early Earth replaced its rocky outer plates with deeper-dwelling mantle rock, said Katie Smart, a geologist at the University of the Witwatersrand and co-author of the new study.

"This means that some sort of recycling mechanism, which we interpret as similar to modern-style plate tectonics, was operating by at least 3.5 billion years ago to move shallow material to the Earth's interior," Smart told Live Science in an email. "This could mean that processes operating on ancient Earth were not so different than those we can observe today." [50 Interesting Facts About the Earth]

Like modern-day Earth, baby Earth may have had its share of volcanoes and earthquakes, Smart added.  

Mysterious early Earth

Nowadays, the lighter continental and oceanic crust floats atop a solid but flowing mantle that encircles the planet's molten iron core. Over time, the layers of crust grind against each other, slip past each other and dive beneath each another in a set of interactions known as plate tectonics. Subduction, in which one plate dives beneath another, helps recycle continental crust deep into the mantle and means that hundreds of millions of years ago, some of the material found deep within the mantle was at Earth's surface, feeling the sun's rays.

But few rocks remain from Earth's early history to recreate what the ancient planet looked like, meaning scientists don't agree on when plate tectonics emerged. Some think the plates began their movement 4 billion years ago, while others say the process began just 1 billion years ago.

"Geoscientists know that some continental crust existed very early in Earth's history," Smart told Live Science in an email. "How much crust existed and how did it form are up for debate, but we do know that there was ancient crust present on Earth prior to the time we hypothesize the Wits diamonds formed."

For instance, traces of Earth's primeval crust can be found in rocks in Canada that are more than 4 billion years old, and vast expanses of 3.8-billion-year-old crust still exist at the surface in Greenland. But those pieces of ancient crust only show that continental crust existed, not that Earth's upper layer was being recycled into the mantle at that time, Smart said.

Ancient diamonds

To get a better picture of the teenage Earth, Smart and her colleagues analyzed diamonds found in a rocky outcropping in Witwatersrand, South Africa. The rocks themselves are among the oldest rocks on Earth, and have been at the surface for at least 3.1 billion years, which suggests the diamonds themselves are even older, they said.

Then, the team analyzed the nitrogen isotopes, or versions of nitrogen with different numbers of neutrons, in the diamonds. Diamonds are mostly carbon, and form when the pressure cooker of Earth's interior squeezes carbon atoms into a tight and orderly crystalline pattern. Nitrogen atoms occasionally get squeezed into this diamond crystal structure, and the way these nitrogen atoms clump together can reveal how long the sparkly gemstones spent at the high pressures and temperatures of the subterranean environment before they reached Earth's surface. In this instance, the nitrogen arrangement revealed that the ancient diamonds had spent between 200 million and 400 million years in the mantle before they reached the surface, suggesting they formed at least 3.5 billion years ago, Smart said. [7 Ways the Earth Changes in the Blink of an Eye]

Next, the team took a closer look at the nitrogen atoms themselves. Compared to rocks in the mantle, rocks exposed to air tend to hold more heavy isotopes of nitrogen, which contain more neutrons.

The team found that up to 3 percent of the nitrogen in the diamonds was nitrogen-15 (meaning it contained eight neutrons, rather than the more common seven). That ratio was much higher than the typical fraction in the mantle or other diamonds, but similar to that found in both ancient and modern crust, the researchers reported Jan. 11 in the journal Nature Geoscience.

The nitrogen data showed that sometime prior to 3.5 billion years ago, crust from the surface had somehow made its way down deep into the mantle, where the diamonds formed.

Old rocks, uncertain implications

The new results shed light on processes on ancient Earth, said Sonja Aulbach, a geologist at Goethe University in Frankfurt, Germany, who was not involved in the study. Because diamonds do not react with other elements in the environment, they've long been viewed as potential "time capsules," but it is often too tricky to date them, Aulbach said.

But these diamonds were trapped within rocks whose age is clearly constrained, so "there is no doubt these stones are very old and that whatever secret they give away bears on processes on Earth that occurred at least 3 billion years ago, Aulbach told Live Science in an email.

The new report also did an excellent job of teasing out "every last bit of information" from the elements and isotopes in the diamonds, Aulbach said.

But while the results clearly show that the crust was recycled somehow during the Earth's early years, plate tectonics aren't the only possible explanation, she said.

"Earth's mantle was much warmer in the Archean [eon that began approximately 4 billion years ago], and there must have been a temperature threshold, above which tectonic processes would have been very different," Aulbach said. "There are alternative dynamic scenarios to recycle surface material — for example, by dripping or sagging rather than true subduction."

Still, plate tectonics is the most straightforward explanation, and other evidence from around the world supports the notion that plate tectonics emerged at least 3 billion years ago, she added.

Follow Tia Ghose on Twitterand Google+. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

Diamonds can form with the help of ancient saltwater, say researchers who have identified the gems that crystallized with the help of oceanic crust dating back as far as 200 million years ago.

This finding could help solve the long-standing mystery of how diamonds form, and shed light on how matter gets cycled between the surface and the deep Earth, scientists added.

Diamonds crystallize under extraordinary heat and pressure. Scientists think the jewels usually form 90 to 150 miles (140 to 250 kilometers) below Earth's surface, in the planet's mantle layer, which is sandwiched between Earth's crust and core. The deepest of these precious stones have come from 430 miles (700 km) below Earth's surface.

Powerful volcanic eruptions can punch through the centers of ancient continents to bring diamonds to Earth's surface, embedding the crystals in rocks known as kimberlites that can be up to 2.1 billion years in age. Formations of Kimberlite are often barren of diamonds; of the 1,500 or 2,000 known kimberlites, miners have found only 50 or 60 that are worth mining. [Sinister Sparkle Gallery: 13 Mysterious & Cursed Gemstones]

Most scientists think diamonds crystallize from some kind of fluid. However, what exactly that fluid might be is controversial.

To help solve this mystery, geochemists analyzed precious stones from the Ekati Diamond Mine in the tundra of Canada's Northwest Territories, the source of Canada's first commercial diamonds. These kimberlites are relatively young, having formed as recently as 45 million years ago.

The diamonds most useful to geochemists are the least commercially viable ones: flawed, dirty-looking diamonds loaded with impurities such as bits of rock and tiny droplets of fluid. These impurities, known as inclusions, lower a stone's commercial value, but can hold secrets about how the gem formed.

"After a diamond captures something, from that moment until millions of years later in my lab, that material stays the same," study lead author Yaakov Weiss, a geochemist at Columbia University's Lamont-Doherty Earth Observatory in the Palisades, New York, said in a statement. "We can look at diamonds as time capsules, as messengers from a place we have no other way of seeing."

The scientists analyzed fluid inclusions within 11 fibrous diamonds — stones that consist of multiple layers instead of a single gem-quality crystal. These droplets were salty, loaded with plenty of chlorine, potassium and sodium, much like seawater.

By pinpointing when the diamonds formed and the composition of their inclusions, the researchers were able to suggest the fluids' origin: a slab of watery oceanic crust that plunged or subducted below western North America about 150 million to 200 million years ago. This occurred underneath what is now the present-day Canadian tundra, where the mines are located. This finding "provides strong evidence tying ancient surface water with diamond formation at depths of 150 to 200 km (93 to 124 miles) below continents," Weiss told Live Science. [In Photos: Ocean Hidden Beneath Earth's Surface]

The scientists do not suggest that diamonds form directly from seawater. Instead, the researchers say fluids from the oceanic crust chemically reacted with solid continental rocks just above them, helping create the right mixture from which diamonds could crystallize, Weiss said.

Understanding diamond formation could shed light on the carbon cycle, the movement of vast amounts of carbon from the Earth's atmosphere and surface into the planet's interior, through activity such as subduction, and then back up again through volcanic eruptions. This cycle plays a key role in controlling climate; for instance, carbon dioxide traps heat from the sun to warm the globe.

It remains uncertain whether all diamonds crystallize with the help of seawater. "Many scientists now believe that both dirty diamonds and gem-quality diamonds form from the same fluids, but this topic is still arguable," Weiss said. "Personally, I am among those that think that most diamonds form in a similar way."

It is also an open question whether this research could help miners find new veins of diamond ore. "If a direct connection between kimberlite eruptions and oceanic subduction can be demonstrated, then it might be wise to look for kimberlites along ancient subduction lines," Weiss said.

The scientists detailed their findings in the Aug. 20 issue of the journal Nature.

Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

SAN FRANCISCO — Here's the perfect Christmas gift for the person who has everything: A red and green rock, ornament-sized, stuffed with 30,000 teeny-tiny diamonds.

The sparkly chunk was pulled from Russia's huge Udachnaya diamond mine and donated to science (the diamonds' tiny size means they're worthless as gems). It was a lucky break for researchers, because the diamond-rich rock is a rare find in many ways, scientists reported Monday (Dec. 15) at the American Geophysical Union's annual meeting.

"The exciting thing for me is there are 30,000 itty-bitty, perfect octahedrons, and not one big diamond," said Larry Taylor, a geologist at the University of Tennessee, Knoxville, who presented the findings. "It's like they formed instantaneously."

The concentration of diamonds in the rock is millions of times greater than that in typical diamond ore, which averages 1 to 6 carats per ton, Taylor said. A carat is a unit of weight (not size), and is roughly equal to one-fifth of a gram, or 0.007 ounces. [Sinister Sparkle Gallery: 13 Mysterious & Cursed Gemstones]

The astonishing amount of diamonds, and the rock's unusual Christmas coloring, will provide important clues to Earth's geologic history as well as the origin of these prized gemstones, Taylor said. "The associations of minerals will tell us something about the genesis of this rock, which is a strange one indeed," he said.

Although diamonds have been desired for centuries, and are now understood well enough to be recreated in a lab, their natural origins are still a mystery.

"The [chemical] reactions in which diamonds occur still remain an enigma," Taylor told Live Science.

Scientists think diamonds are born deep below Earth's surface, in the layer between the crust and core called the mantle. Explosive volcanic eruptions then carry hunks of diamond-rich mantle to the surface. However, most mantle rocks disintegrate during the trip, leaving only loose crystals at the surface. The Udachnaya rock is one of the rare nuggets that survived the rocketing ride. 

Taylor works with researchers at the Russian Academy of Sciences to study Udachnaya diamonds. The scientists first probed the entire rock with an industrial X-ray tomography scanner, which is similar to a medical CT scanner but capable of higher X-ray intensities. Different minerals glow in different colors in the X-ray images, with diamonds appearing black.

The thousands upon thousands of diamonds in the rock cluster together in a tight band. The clear crystals are just 0.04 inches (1 millimeter) tall and are octahedral, meaning they are shaped like two pyramids that are glued together at the base. The rest of the rock is speckled with larger crystals of red garnet, and green olivine and pyroxene. Minerals called sulfides round out the mix. A 3D model built from the X-rays revealed the diamonds formed after the garnet, olivine and pyroxene minerals.

Exotic materials captured inside diamonds, in tiny capsules called inclusions, can also provide hints as to how they were made. The researchers beamed electrons into the inclusions to identify the chemicals trapped inside. The chemicals included carbonate, a common mineral in limestone and seashells, as well as garnet.

Altogether, the findings suggest the diamonds crystallized from fluids that escaped from subducted oceanic crust, likely composed of a dense rock called peridotite, Taylor reported Monday. Subduction is when one of Earth's tectonic plates crumples under another plate. The results will be published in a special issue of Russian Geology and Geophysics next month (January 2015), Taylor said.

The unusual chemistry would represent a rare case among diamonds, said Sami Mikhail, a researcher at the Carnegie Institution for Science in Washington, D.C., who was not involved in the study. However, Mikhail offered another explanation for the unusual chemistry. "[The source] could be just a really, really old formation that's been down in the mantle for a long time," he said.

Follow Becky Oskin @beckyoskin. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.

A meteorite that crashed down in California's gold country is showing off treasures of a different sort: small diamonds that could tell scientists more about the insides of asteroids.

The Sutter's Mill meteorite smashed into the ground on April 22, 2012, after a fiery entry that caught the attention of professional and amateur observers alike. A scientific team raced against rain to pick up meteorite fragments before water polluted the samples. Their efforts helped to produce a cosmic jackpot.

Embedded in part of the meteorite were 10-micron diamond grains — much smaller than what is used in diamond rings. But their diminutive size is still bigger than what is usually found in meteorites. The finding hints at what could have existed in the parent cosmic body that eventually broke apart and produced the Sutter's Mill meteoroid before the fragment slammed into Earth's atmosphere. [Photos: Fireball Drops Meteorites on California]

“Sutter's Mill gives us a glimpse of what future NASA spacecraft may find when they bring back samples from a primitive asteroid," lead researcher Peter Jenniskens, who holds dual affiliations at the SETI Institute and at NASA's Ames Research Center, said in a statement. "From what falls naturally to the ground, much does not survive the violent collision with Earth's atmosphere."

Diamonds weren't all that researchers found. More fragments revealed isotopes of an element called chromium. The different types of chromium reveal that at least five stars sent material to the young solar system about 4.5 billion years ago, with some of the materials still sticking around in the meteorite, scientists found.

"The formation of the solar system did not fully erase and homogenize these signatures, and Sutter’s Mill provides the clearest record yet," Qing-Zhu Yin, the Sutter's Mill Meteorite Consortium lead in isotope and trace element geochemistry, said in the same statement.

The small body had a complicated history after that, with liquid water permeating some fragments (producing minerals such as calcium and magnesium carbonate). This could have been an indication of radiation in the meteorite's parent body, which heated ice beyond the melting point.

Other unusual elements — such as a calcium sulfide called oldhamite — also indicate heating in the parent body, as well as in areas that were not heated at all. Heating also came when the fragment was sailing on its own. Sometime in the past 100,000 years, the meteoroid was heated up to at least 572 degrees Fahrenheit (300 degrees Celsius). This heating could have happened during the entry into Earth's atmosphere, the researchers said.

"I don't know of any similar meteorites that contain both heated and unheated materials," said team member Mike Zolensky, a space scientist at NASA's Johnson Space Center in Houston.

The heated portions caused other changes inside the meteorite's interior, such as the removal of volatile organic compounds. Scientists also managed to track down amino acids (protein building blocks) inside the meteorite.

Thirteen papers based on the findings were recently published in the journal Meteoritics and Planetary Science.

Follow Elizabeth Howell @howellspace. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

Diamonds are the hardest naturally occurring minerals known to man. Even so, scientists are working to make them even tougher, in order to use the sparkling gems as tools for cutting.

Now, a team of researchers, led by Yongjun Tian and Quan Huang at Yanshan University in China, has created synthetic diamonds that are harder, meaning they are less prone to deformation and breaking, than both natural and other man-made diamonds.

To create these tougher-than-steel diamonds, the researchers used tiny particles of carbon, layered like onions, and subjected them to high temperatures and pressures. The resulting diamonds had a unique structure that makes them more resistant to pressure and allows them to tolerate more heat before they oxidize and turn to either gas (carbon dioxide and monoxide) or ordinary carbon, losing many of their unique diamond properties. [In Photos: 13 Mysterious & Cursed Gemstones]

First, a bit about diamonds: Gem-quality diamonds are single crystals, and they are quite hard. But artificial diamonds used on tools are harder still. That's because they are polycrystalline diamonds, or aggregates of diamond grains called domains, that measure a few micrometers or nanometers across. The grains help to prevent the diamond from breaking, as the boundaries act like small walls that keep chunks of diamond in place. The smaller the domains are, the stronger the diamond.

Tian's team used the onionlike carbon nanoparticles to make diamonds with domains that are a few nanometers in size and are mirror images of each other. Such "nanotwinned" crystals are much harder than ordinary diamonds, by a factor of two.

The team tested the artificial diamond's hardness by pressing a pyramid-shaped piece of diamond into the nanotwinned diamond. Tian's group made a small indentation in their artificial diamond, applying pressures equivalent to nearly 200 gigapascals (GPa) — about 1.9 million atmospheres. An ordinary natural diamond would crush under just half that pressure.

The team also tested how hot the nanotwinned diamond could get before oxidizing. In two different tests, they found that the ordinary diamond began to oxidize at about 1,418 and 1,481 degrees Fahrenheit (770 and 805 degrees Celsius), depending on the testing method. The nanotwinned diamonds didn't oxidize until they reached 1,796 or 1,932 F (980 or 1,056C).

But not everyone is convinced by these results. Natalia Dubrovinskaia, a professor of material physics at the University of Bayreuth in Germany, said she doesn't trust the pressure tests. If what Tian's group is reporting is true, the indenter should have broken, because the material of the indenting tool is not as hard as the nanotwinned diamond, she told Live Science in an email.

Tian disagreed with Dubrovinskaia's assessment of the indenter. He said that it is possible to measure pressure on the nanotwinned diamond because the indenter was pushed from a vertical position and the amount of shearing force on it wasn't enough to damage it.

Tian and Dubrovinskaia have "sparred" before; last year, the Yanshan lab said it demonstrated a similar phenomenon, making a form of ultrahard cubic boron nitride. At the time, Dubrovinskaia voiced similar concerns.

Tian, meanwhile, stands by his work. "Indentation hardness of any material can be measured reliably using [a] diamond indenter when the indenter axis is exactly perpendicular to the smooth surface of [the] tested sample," he said.

Another scientist, Ho-Kwang Mao, of Argonne National Laboratory in Illinois, thinks Tian's work is valid; he noted that an indenter could reliably measure the hardness of materials much harder than itself.

In addition, the novel part of the work is that such a hard material has been created in a way that can be readily reproduced. "They created a bulk material," Mao said. "They succeeded in making this and making it harder than diamond — that's novel."

The new study is detailed in the June 12 issue of the journal Nature.

Follow us @livescience, Facebook & Google+. Original article on Live Science.

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

One of great challenges of the 21st century has been to develop ways to manipulate matter on smaller and smaller dimensions.

As the great physicist Richard Feynman noted in his famous 1959 lecture, “There’s plenty of room at the bottom”, and this adage is currently playing out with unprecedented vigour.

Nanomachines, quantum computing components and ultrafast electronics are all important areas that are benefiting from this extreme push for engineering on the ultra-nanoscale.

How small can you cut?

To date, lasers have been tremendously successful tools for manipulation of matter on small scales but only to a certain point. Despite their ability to drill and cut materials to within a human hair’s width, they have notoriously poor resolution on the atomic scale.

The fundamental reason for this is that conventional laser machining relies on heating the material, with atoms ejected from the surface by the resulting explosive forces and vaporisation. As a result, many atoms get caught up in the process making it impossible to achieve the resolution needed – it is like trying to pick out a grain of salt using a blow torch.

Improving resolution was thought to be a rather hopeless situation. But there now seems to be a new pathway forward, at least for some materials.

We have now discovered that lasers can be made to split apart the chemical bonds holding atoms together without any significant collateral damage into the surrounding material.

Focus on diamonds

The critical experiment involved an ultraviolet laser beam on a diamond surface.

It was found that the probability for ejection of the carbon atoms that comprise the crystal lattice was sensitive to the laser beam’s polarisation (that is, the direction of the light wave’s beating movement) with respect to the direction of chemical bonds that hold the material together.

In the chaotic environment of a laser heated surface, this kind of selective atom removal hasn’t been feasible.

Like many good scientific discoveries, this one was discovered entirely by accident.

On close examination of surfaces exposed to a UV laser we observed regular nano-patterns of size on the molecular scale. The key observation, reported in Nature Communications today, is that the shape and orientation of these patterns are dependent on the alignment of the laser polarisation with the way atoms line up in the crystal lattice.

As laser polarisation was altered a rich variety of patterns were produced. Some were reminiscent of natural forms such as ripples on the beach (picture above), and revealing partial images of the underlying symmetries contained in the arrangement of atoms that make up the crystal.

Take that, atom by atom

The results show for the first time that a laser beam can target specific atoms on the surface, in a way not yet entirely understood, causing their chemical bonds to break before there is any significant dissipation of energy into the surrounding area.

The significance of the result is that it is possible for lasers to interact with pairs of atoms and cause their separation without disturbing the surroundings. In the case of diamond, we used light polarisation to select what atom pairs are targeted by the laser beam.

That this effect has been first achieved in diamond is very convenient. Diamond is a material that, although it’s been available in raw form for millennia, is only now gaining great importance in science and technology. This recent surge in interest is a result of low-cost production of high-quality diamond material from synthetic sources.

Potential uses of such a small cut

This discovery can therefore be readily exploited in the many cutting-edge areas of diamond technology such as for fabrication of quantum processors and miniature high-power lasers.

So far the effect has been seen across the broad area of the laser beam. Although this may be useful in itself for rapid nano-texturing of surfaces, for example, a major focus of future research is to demonstrate the ultimate control of single atoms on a surface.

About 25 years ago, IBM in the US demonstrated the ability to construct alphabet characters out of single atoms on the surface of a metal using the sharp tip of scanning probe microscope.

But in that instance, and in much other related work since, this procedure only works for atoms that are very weakly bound to the surface. Now, we have the exciting prospect being able to manipulate the strong atomic bonds that make up a solid including super-strongly bonded materials like diamond.

It is likely that the fact we observed this effect in diamond is no coincidence since this is a material with very highly defined bonds that are relatively disconnected from neighbouring atoms.

The key question now is – how many other materials reveal this effect?

Rich Mildren receives research funding from the Australian Research Council and the Asian Office of Aeronautical Research and Development.

This article was originally published on The Conversation. Read the original article. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

Evidence of Earth's first continents — 4.3-billion-year-old "diamonds" — are actually just fragments of polishing grit, a new study finds.

In 2007, an international team first reported discovering the tiny gems, which hid in pockets inside zircon crystals from Western Australia's Jack Hills, in the journal Nature. But it turns out that the gems weren't actually diamonds, but polishing paste, smushed into hairs'-width cracks when the zircons were prepared for laboratory tests, according to a study published online in the Feb. 1, 2014, edition of the journal Earth and Planetary Science Letters.

Scientists at the University of California, Riverside (UCR) found the mistake by snapping pictures of the disputed diamonds with a powerful transmission electron microscope, along with other techniques. Instead of bumpy real diamonds, they discovered sharp-corned synthetic diamonds embedded in polishing compound.

"There can be no doubt of the images we show," said Harry Green, a UCR research geophysicist and study co-author. "Polishing the specimens with grinding compound that was made of diamonds was a terrible mistake."

The original authors, who provided their samples for analysis by Green and lead study author Larissa Dobrzhinetskaya, also agree with the conclusions.

"Back then, we were convinced that the diamonds are real due to apparently clear evidence," said Thorsten Geisler-Wierwille, co-author of the 2007 study. "We agree with the final conclusion of Dobrzhinetskaya and co-workers."

Windows in time

Zircons are the oldest evidence of rocks on Earth's surface — tiny but tough survivors of the planet's hellish early years. In the 1980s, scientists discovered Jack Hills zircon crystals as old as 4.4 billion years within 3-billion-year-old conglomerates, a sedimentary rock similar to pebbly stream deposits. Because the zircons are much, much older than the conglomerate, the minerals must have washed into the conglomerate, eroded out of Earth's oldest rocks. [Have There Always Been Continents?]

A single Jack Hills zircon is like a time capsule from the beginning of the Earth. The crystal's microscopic bubbles and inclusions trap elements that hint at the composition and atmosphere of the young planet. Even though the Jack Hills rocks have been buried, heated and squeezed in the past 3 billion years, scientists have shown that zircons can emerge from these metamorphic processes relatively unscathed, preserving their original history.

"These zircons are of extraordinary importance," Green said.

So it was a big deal when the international team, led by German geochemist Martina Menneken, reported discovering diamonds inside Jack Hills zircons. The findings, published Aug. 23, 2007, in the journal Nature, reported bits of diamonds ranging from 4.3 billion to 3.1 billion years old within individual zircons. Most diamonds were just a few times wider than a human hair.

The presence of diamonds meant the young Earth was cool enough to make relatively thick continental crust. Many modelers have suggested that Earth was covered by a roiling lava sea for its first 500 million years — an era called the Hadean, for its hellishly hot temperatures. But diamond means that the surface was cold enough to crystallize miles-thick chunks of rock, under which diamonds form. The findings also supported the idea that plate tectonics was in motion, with plates of crust skidding about and colliding, creating the pressures that form diamonds.

But some scientists, including Dobrzhinetskaya, were suspicious of the findings, because Menneken and her colleagues polished the zircons with diamond paste. They also found it hard to believe that a single zircon could have diamonds that ranged in age across more than 1 billion years.

"The story was extraordinarily difficult to buy," Green said.

Contamination from diamond-polishing paste is a common problem for a different group of diamond experts — those who specialize in studying ultra-high-pressure rocks. These are some of the most extreme rocks on Earth, forged at great pressures in tectonic collision zones and then brought to the surface. Diamonds are a key clue to hunting down these ultra-high-pressure zones.

Science self-corrects

Dobrzhinetskaya is an expert in ultra-high-pressure diamonds, with a suite of high-tech equipment specially tuned for analyzing these minerals. Several years ago, she asked the German researchers to let her test the Jack Hills zircons, and the team willingly agreed.

"We were also interested in [transmission electron microscope, or TEM] results and, at that time, had no possibility to perform TEM investigations by ourselves," Geisler-Wierwille told LiveScience in an email interview.

The UCR scientists discovered the size and shape of the diamond crystals were more similar to those seen on angular synthetic diamonds. Instead of growing in place, with interlocking fingers grasping the zircon, the diamonds simply sat in their voidlike homes. The diamonds were also surrounded by flecks of minerals that matched the composition of the polishing compound and epoxy resin used in the German lab that prepped the zircons. [Oops! The 5 Greatest Scientific Blunders]

"These things are diamond paste," Green said. But the collaboration broke down when it came time to publish the results. While both groups agree that polishing paste got inside the Jack Hills zircons, Geisler-Wierwille thinks that there still could be early-Earth diamonds embedded more deeply, in the core of the zircon crystals, which are only about as wide as mechanical-pencil lead (0.3 millimeters).

Green strongly disagrees. "They can go back to their cache of Jack Hill zircons and make new specimens," Green said. "If you're a betting person, I'll make you a bet that they won't find it. There have been an enormous amount of [Jack Hills] zircons analyzed in a bunch of different ways, and no one has ever found diamonds."

Indeed, the German team went back and picked through about 1,000 zircons in search for more diamonds from their samples and didn't find a single microscopic gem. (They do report finding graphitelike carbon, but that's another story in itself.)

Struggle to publish

Based on the TEM images, both groups agree the "diamonds" cited in the 2007 Nature paper come from polishing-paste diamonds. But because of the disagreement over whether diamonds could be found in other zircons, Geisler-Wierwille's group declined to add their names as co-authors on the study by Dobrzhinetskaya and Green. Instead, the German-led team wrote their own paper, using similar methods.

But both studies were rejected when submitted for publication in scientific journals. Dobrzhinetskaya's was rebuffed by Nature and Geisler-Wierwille's (with Martina Menneken as first author) by the journal American Mineralogist.

Nature declined to comment on the rejection. However, Green said reviewers agreed with Geisler-Wierwille — there was a possibility that some zircons held real diamonds. (Outside experts review studies for research journals and provide their opinion on whether it is worthy of publication.)

But at Earth and Planetary Science Letters, reviewers agreed there was no wiggle room, said Mark Harrison, a geochemist at the University of California, Los Angeles who serves on the journal's editorial board and accepted the paper for publication.

"I had three people review Larissa [Dobrzhinetskaya]'s paper, and nobody could see any way out of it," Harrison told LiveScience. Harrison is also an expert on Jack Hills zircons, and he said he has analyzed thousands of the zircons without ever finding a diamond.

Because the Jack Hills diamonds have been used to support models for early Earth cooling, Harrison hopes the new study corrects the record. "It's important that people stop wasting their time," Harrison said. "The early Earth was called Hadean for a reason. Personally, I disagree with that because I think we've found legitimate [zircon] inclusions of other low-temperature minerals, but I don't think we've found diamonds."

Email Becky Oskin or follow her @beckyoskin. Follow us @livescience, Facebook & Google+. Original article on LiveScience.

In quite an eerie feat, physicists have floated microscopic diamonds in midair using laser beams.

Researchers have already used lasers to levitate extremely small particles, such as individual atoms, but this is the first time that the technique has worked on a nanodiamond, which, in this case, measures just 100 nanometers (3.9 x 10^-8 inches) across, or more than 1,000 times thinner than a fingernail.

In the new study, the physicists from the University of Rochester relied on the fact that a laser beam, which is made up of photons, creates a tiny force that usually can't be felt. [Wacky Physics: The Coolest Little Particles in Nature]

"If we turn on a light or open a door and feel the sun, we don't feel this push or pull," study researcher Nick Vamivakas said in a video released by the university. "But it turns out that if you focus a laser down with a lens to a very small region of space, it can actually pull on microscopic, nanoscopic particles."

To force the tiny diamonds to float, Vamivakas and his colleagues focused a pair of lasers toward a clear vacuum chamber and then sprayed the diamonds into the chamber using an aerosol dispenser. The diamonds gravitated toward the light, and some eventually levitated in a stable position.

Sometimes, the levitation occurred within just a couple of minutes, while other times, the process took a bit longer.

"Other times, I can be here for half an hour before any diamond gets caught," Levi Neukirch, a graduate student at the University of Rochester who was involved in the study, said in a statement. "Once a diamond wanders into the trap, we can hold it for hours."

The team hopes the findings will have applications in quantum computing and, more theoretically, help explain how friction operates on extremely small scales.

"The position of the crystal in the trap is a very sensitive probe of forces in its environment," Vamivakas said in the university video. "The reason this is important is, as technology continues to shrink down to these length scales, we need to understand how the environment will interact with the devices that we are making."

The team plans to continue its experiments in order to better understand the physical behavior of the crystals, which could help address other basic unanswered questions in physics. 

The levitation experiment is detailed this week in the journal Optics Letters. 

Follow Laura Poppick on Twitter. Follow LiveScience on Twitter, Facebook and Google+. Original article on LiveScience.

India may contain a natural trove of diamonds previously overlooked by prospectors, new research shows.

Canada, Russia and southern Africa currently dominate the world diamond market. But, in recent years, geologists have debated whether southeast India could produce large quantities of diamonds as well. Now, research from a group of geologists at the National Geophysical Research Institute in Hyderabad, India, suggests that southeastern regions of the country do, in fact, contain the right ingredients for these gems to form in abundance. A report of their findings appeared earlier this month in the journal Lithosphere.

Diamonds form deep within the Earth's mantle and erupt to the surface within volcanic rocks called kimberlites and lamproites. The team discovered such diamond-bearing rocks by chance while conducting an unrelated geologic survey and decided to investigate the sites further as a side project.

"We thought that it may be a good idea to conduct further research on this crucial aspect to propose a suitable and cost-effective reconnaissance technique that can be deployed as a quick search tool over large areas for diamond prospecting," said geologist Subrata Das Sharma, an author on the paper. [Shine On: Photos of Dazzling Mineral Specimens]

Diamond-forming conditions

Instead of tediously searching an entire landscape for diamond-bearing rocks — which tend to crumble easily and are often difficult to identify — geologists have devised a variety of techniques to search for key diamond-forming conditions within the mantle, and then later explore promising areas on land.

These diamond-forming conditions include extremely high temperatures and pressures, found only in the deepest depths of the Earth's lithosphere — a region including the entire Earth's crust and the solid upper mantle that rests above the more molten lower mantle where crystals melt into magma.

Without the heat and pressure of the deep lithosphere, carbon — the only ingredient in diamonds — takes on the less valuable form of graphite.

The lithosphere varies in thickness across the planet, and does not always reach depths deep enough to facilitate diamond growth. Das Sharma and his team sought to find out how thick the lithosphere is under India, and did so by looking at seismic data collected during several relatively recent earthquakes. Since seismic waves travel at different speeds and amplitudes depending on the material they pass through, seismic data can reveal the transition from the hard upper mantle to the molten lower mantle, which is the lower boundary of the lithosphere.

Previous studies based on seismic data have suggested that southeastern India rests atop a thin portion of the lithosphere. But Das Sharma and his team reanalyzed related data using different techniques, and discovered a signal much deeper indicating the lithosphere reaches down far enough to facilitate diamond growth.

The team also examined existing analyses of the chemical composition of nearby rocks on the surface to further confirm that the temperature and pressure conditions would have been extreme enough to support diamond growth.

Indian diamond mining?

Ultimately, the researchers identified a region wider than 120,000 square miles (200,000 square kilometers) across southeastern India that could potentially contain diamond-bearing rocks. 

These findings could lead to increased diamond mining in the country, but this will depend on the interests of mining companies, Das Sharma said.

"Diamond mining could become viable once an appropriate mining strategy is worked out," Das Sharma said. "This needs concerted efforts in field detection of generally obscured kimberlites and lamproites in a region." [Infographic: Tallest Mountain to Deepest Ocean Trench]

While the team's techniques are relatively quick and cheap, geologists elsewhere have developed other efficient methods for diamond prospecting as well. For example, some use electromagnetic tools that measure the conductivity of the mantle in search of carbon-rich areas (because carbon is highly conductive, or allows for the easy flow of electrons), while others use seismic imaging techniques that illustrate physical boundaries within the mantle.

Still, this new study demonstrates how to use effective and relatively cheap techniques that could help smooth the way for future diamond exploration programs around the world, according to Alan Jones, a geologist at the Dublin Institute for Advanced Studies in Ireland who was not involved in the study.

"This has really cleared up this Indian lithosphere issue," Jones told LiveScience. "In terms of global impact, I would say the paper is on part of the cutting edge along with other people's work."

The team members plan to share their results with the Indian government, and to continue honing their research methods to develop even more efficient diamond-hunting techniques.

Follow Laura Poppick on Twitter. Follow LiveScience on Twitter, Facebook and Google+. Original article on Live Science.