sedimentary
Ironstone Concretion (Moqui Marble)
Iron Oxide Concretion (Goethite and Hematite around a Sandstone core)
Hardness: 5-5.5 (outer shell); Color: Brown, tan, or dark rusty orange; Luster: Dull/Earthy; Structure: Spheroidal/Concretionary; Cleavage: None
- Hardness
- 5-5
- Color
- Brown, tan, or dark rusty orange
- Luster
- Dull/Earthy
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Physical properties
Hardness: 5-5.5 (outer shell); Color: Brown, tan, or dark rusty orange; Luster: Dull/Earthy; Structure: Spheroidal/Concretionary; Cleavage: None
Formation & geological history
Formed by the precipitation of iron oxide minerals from groundwater flowing through porous sandstone, typically within the last few million years in Jurrasic-aged formations.
Uses & applications
Predominantly used as decorative collector specimens, metaphysical 'healing stones', and small landscaping accents.
Geological facts
Also known as Moqui Marbles, Shaman Stones, or Navajo Cherries. They often have a 'rattle' effect if the inner sandstone core becomes loose from the iron shell.
Field identification & locations
Identify by their perfectly round to disc-like shape, high weight for their size, and rough, weathered exterior surface. Commonly found in the Navajo Sandstone of the Southwest US.
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