sedimentary
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)
Hardness: 5-6 (shell), 7 (core); Color: Rusty brown to dark chocolate outer shell, tan interior; Luster: Dull, earthy; Crystal structure: Amorphous/microcrystalline shell, granular core; Specific gravity: 3.3-4.3 (shell)
- Hardness
- 5-6 (shell), 7 (core)
- Color
- Rusty brown to dark chocolate outer shell, tan interior
- Luster
- Dull, earthy
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Physical properties
Hardness: 5-6 (shell), 7 (core); Color: Rusty brown to dark chocolate outer shell, tan interior; Luster: Dull, earthy; Crystal structure: Amorphous/microcrystalline shell, granular core; Specific gravity: 3.3-4.3 (shell)
Formation & geological history
Formed in the Jurassic Navajo Sandstone (approx. 180-190 million years old) through a precipitation of iron minerals from groundwater moving through porous sandstone, often collecting around a small organic nucleus.
Uses & applications
Primarily used as metaphysical 'healing' stones, educational geological specimens, and decorative items. Not used in heavy industry or construction due to size and varying structural integrity.
Geological facts
They are named after the Hopi people (formerly known as the Moqui). Similar spherical concretions have been discovered on Mars by the Opportunity rover, where they are colloquially referred to as 'blueberries'.
Field identification & locations
Identify by their spherical or puck-like shape and distinct iron skin. Commonly found in the American Southwest (Utah/Arizona). Note: Collecting within National Parks is illegal; specimens found on private land are the main source for collectors.
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