Photo Gallery: Fantastic Moqui Marbles

Game of stones

moqui marbles

(Image credit: Marjorie Chan, University of Utah)

Moqui marbles on a sandstone slope. A new study reveals that the moqui marbles are less than 25 million years old.

Unusual find

Iron concretions, Zion National Park

(Image credit: NPS)

The unusual geologic formations are concretions — sandstone balls cemented by a hard shell of iron oxide minerals.

Amazing view

Zion National Park

(Image credit: National Park Service)

Millions of years in the past, a mixture of water and natural gas flowed through the Navajo Sandstone, bleaching the rocks from red to creamy white. The stolen iron became the moqui marbles.

Checkerboard Mesa

Checkerboard Mesa, Zion National Park

(Image credit: NPS)

At Checkerboard Mesa in Zion National Park, the Navajo Sandstone is creamy white.

Red rocks

Navajo Sandston arch, Zion National Park

(Image credit: National Park Service)

The lower levels of Navajo Sandstone at Zion are stunning red, orange and peach colors.

Field of dreams

moqui marbles

(Image credit: Marjorie Chan, University of Utah)

The concretions collect in topographic lows.

Oddballs

moqui marbles

(Image credit: National Park Service)

Moqui marbles come in many shapes and sizes.

Hard stuff

Navajo sandstone

(Image credit: National Park Service)

Resistant iron minerals erode more slowly than the softer sandstone.

Lumps and bumps

moqui marbles

(Image credit: Marjorie Chan, University of Utah)

The spheres grew layer by layer, making contact with others nearby until many spheres became one large ball.

Fine polish

moqui marbles

(Image credit: Marjorie Chan, University of Utah)

Wind-blown sand polishes the outer shell of hematite or goethite.

Bleached clean

moqui marbles

(Image credit: Marjorie Chan, University of Utah)

Moqui marbles emerge from cream-colored Navajo sandstone.