sedimentary
Moqui Marble
Ironstone Concretion (Goethite/Hematite)
AI-generated identification · may be incorrectHardness: 5-5.5 | Color: Dark brown to black outer shell with tan/yellow sand interior | Luster: Dull to sub-metallic | Crystal Structure: Amorphous/Microcrystalline | Shape: Spherical to sub-spherical
- Hardness
- 5-5
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Physical properties
Hardness: 5-5.5 | Color: Dark brown to black outer shell with tan/yellow sand interior | Luster: Dull to sub-metallic | Crystal Structure: Amorphous/Microcrystalline | Shape: Spherical to sub-spherical
Formation & geological history
Formed as iron oxides (hematite and goethite) precipitated from groundwater around a nucleus in porous sandstone, often during the Jurassic period (Navajo Sandstone).
Uses & applications
Primarily used as metaphysical stones ('shaman stones'), geological educational specimens, and for decoration/collecting.
Geological facts
Identical spherical iron concretions have been discovered on Mars, where NASA scientists nicknamed them 'blueberries.' Their presence suggests water was once present.
Field identification & locations
Identify by their distinct spherical shape, dark iron-based shell, and tendency to occur in groups scattered across desert sandstone landscapes. Commonly found in Utah, USA.
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