sedimentary

Ironstone Concretion (Boji Stone/Moqui Marble type)

Goethite/Hematite-encrusted Sandstone Concretion

AI-generated identification · may be incorrect

Hardness: 5.0-6.0; Color: Dark brown, rusty orange, or black; Luster: Dull to metallic; Crystal Structure: Amorphous or microcrystalline coating; Specific Gravity: 3.4-5.0.

Hardness: 5
Color: Dark brown, rusty orange, or black
Luster: Dull to metallic

Identified April 3, 2026More sedimentary →

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Physical properties

Hardness: 5.0-6.0; Color: Dark brown, rusty orange, or black; Luster: Dull to metallic; Crystal Structure: Amorphous or microcrystalline coating; Specific Gravity: 3.4-5.0.

Formation & geological history

Formed by the precipitation of iron oxide minerals from groundwater within sedimentary rock layers, often around a nucleus like a leaf, shell, or fossil. They typically range from the Jurassic to the Cenozoic era.

Uses & applications

Primarily used as a collector's specimen, in metaphysical practices (referred to as Shaman stones), and occasionally studied to understand groundwater flow in geological history.

Geological facts

Similar structures have been found on Mars by the Opportunity rover, where they are nicknamed 'blueberries,' suggesting the past presence of water on the red planet.

Field identification & locations

Identify by its spherical or disc shape, heavy weight relative to size (due to iron content), and a rough, pitted, or 'brain-like' surface texture. Commonly found in deserts and badlands.