sedimentary

Moqui Marble

Iron Oxide Concretion (Fe2O3 / FeO(OH))

AI-generated identification · may be incorrect

Hardness: 5-6 (outer shell); Color: dark brown, rusty red, or black; Luster: earthy or dull; Crystal structure: orthorhombic (Goethite) or trigonal (Hematite); Cleavage: none; Specific Gravity: varies (dense shell with sandy interior).

Hardness: 5-6 (outer shell)
Color: dark brown, rusty red, or black
Luster: earthy or dull

Identified May 27, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the precipitation of iron oxide minerals from groundwater flowing through porous sandstone. These specifically occur in the Navajo Sandstone (Utah, USA) and are approximately 130 to 180 million years old (Jurassic age).

Uses & applications

Primarily used as metaphysical 'shaman stones,' educational specimens for geology, and for decorative collecting. In the past, they were used by indigenous people for games.

Geological facts

The name 'Moqui' comes from the Hopi people, who once lived in the areas where these are found. Legend says the spirits of the ancestors come to play games with these marbles at night and leave them for the living in the morning.

Field identification & locations

Identify by their near-spherical or disc shape and distinct dark, crunchy iron-oxide shell surrounding a lighter sandstone core. Found commonly in the American Southwest, particularly Utah.