sedimentary
Moqui Marble (Shaman Stone)
Ironstone Concretion (Fe2O3) - primarily Hematite or Goethite shell with Sandstone core
Hardness: 5-6 (outer shell); Color: Dark brown to rusty black exterior, tan interior; Luster: Dull, earthy, or metallic; Crystal Structure: Amorphous/Microcrystalline; Cleavage: None; Shape: Spheroidal/Concretionary.
- Hardness
- 5-6 (outer shell)
- Color
- Dark brown to rusty black exterior, tan interior
- Luster
- Dull, earthy, or metallic
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Physical properties
Hardness: 5-6 (outer shell); Color: Dark brown to rusty black exterior, tan interior; Luster: Dull, earthy, or metallic; Crystal Structure: Amorphous/Microcrystalline; Cleavage: None; Shape: Spheroidal/Concretionary.
Formation & geological history
Formed through the precipitation of iron-rich minerals from groundwater within Navajo Sandstone layers. They are estimated to be between 2 to 25 million years old (Late Tertiary to Quaternary) despite being found in much older rock formations.
Uses & applications
Predominantly used as metaphysical 'healing stones', geological curiosities for collectors, and educational displays. Historically used by Hopi tribes as gaming stones or talismans.
Geological facts
They are often called 'Blueberries' and look strikingly similar to the hematite spherules found by the Mars Rover Opportunity on the Martian surface, suggesting similar aqueous processes on Mars.
Field identification & locations
Identify by their distinct spherical shape, pitted 'orange peel' surface texture, and heavy weight relative to size. Found extensively in the Grand Staircase-Escalante National Monument in Utah, USA. Note: Collecting is strictly regulated or prohibited inside National Parks.
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