sedimentary

Moqui Marble

Ironstone Concretion (Goethite/Hematite layered over Sandstone)

AI-generated identification · may be incorrect

Hardness: 5-5.5 (outer shell); Color: dark brown to rusty red; Luster: dull to sub-metallic; Crystal structure: Orthorhombic (Goethite component); Specific Gravity: 3.3-4.3.

Hardness: 5-5
Color: dark brown to rusty red
Luster: dull to sub-metallic

Identified June 19, 2026More sedimentary →

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Physical properties

Hardness: 5-5.5 (outer shell); Color: dark brown to rusty red; Luster: dull to sub-metallic; Crystal structure: Orthorhombic (Goethite component); Specific Gravity: 3.3-4.3.

Formation & geological history

Formed by the precipitation of iron oxides from groundwater flowing through porous sandstone layers, often during the Jurassic period (Navajo Sandstone).

Uses & applications

Primarily collected as geological curiosities, used in metaphysical practices, and occasionally displayed in educational exhibits.

Geological facts

The name 'Moqui' comes from the Hopi word for the deceased; legend says ancestors come to Earth at night to play games with the spheres.

Field identification & locations

Identify by their distinct spherical or disk shape and dark iron-rich outer rinds. Commonly found in the American Southwest, specifically southern Utah.