Atomic Number: 25
Atomic Symbol: Mn
Atomic Weight: 54.938045
Melting Point: 2,275.8 F (1,246 C)
Boiling Point: 3,741.8 F (2,061 C)
Word origin: The word manganese comes from the Latin word magnes (magnet).
Discovery: Manganese was recognized as a distinct substance by Carl Wilhelm Scheele, Torbern Olof Bergman, and others. It was isolated in 1774 by Johan Gahn by reducing the dioxide with carbon. [See Periodic Table of the Elements]
Properties of manganese
Manganese is a gray-white metal that resembles iron but is harder and very brittle. It is chemically reactive and slowly decomposes in cold water.
The pure metal exists in four allotropic forms. The alpha form is stable at ordinary temperatures. The gamma form changes to the alpha form at ordinary temperatures. In contrast to the alpha form, the gamma form is soft, flexible and easily cut.
Sources of manganese
Manganese minerals are abundant on Earth, especially its oxides, silicates and carbonates. Manganese dioxide (pyrolusite) and manganese carbonate (rhodochrosite) are the most common manganese minerals.
Most manganese today is found in mineral ores in Russia, Brazil, Australia, South Africa, Gabon and India. Large quantities of manganese nodules can be found on the ocean floor. They contain about 24 percent manganese and may become a source of the metal in the future.
Uses of manganese
It is most commonly used in steel products because it adds stiffness, strength and resistance to the alloy. It also improves the forging and rolling qualities of steel.
Manganese is commonly used to form an aluminum alloy. It is also used as a ferromagnetic (to produce magnetic properties) alloy, along with aluminum, antimony and small amounts of copper.
Manganese dioxide is used to depolarize dry cell batteries, to reduce discoloration of green glass and even to help dry black paint.
Manganese is the coloring agent that causes the violet hue in natural amethyst. It’s also used to create the same color in amethyst glass.
The permanganate is a powerful oxidizing agent and is used in medicine. Manganese is an important trace element in nutrition and is important in how our body utilizes vitamin B1. However, exposure to manganese in high quantities can be toxic.
(Source: Los Alamos National Laboratory)