sedimentary
Soil Concretion / Clay Clod
Pedogenic concretion / Indurated clay aggregate
AI-generated identification · may be incorrectHardness 1-2.5 on Mohs scale; earthy brown to ochre color; dull, earthy luster; amorphous/granular texture; low specific gravity (~1.8-2.4).
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Physical properties
Hardness 1-2.5 on Mohs scale; earthy brown to ochre color; dull, earthy luster; amorphous/granular texture; low specific gravity (~1.8-2.4).
Formation & geological history
Formed by the precipitation of mineral cements (such as iron oxides or calcium carbonate) binding clay and silt particles in soil horizons during wet-dry weathering cycles.
Uses & applications
No major commercial or jewelry value; useful as an indicator of soil development, hydrology, and weathering processes.
Geological facts
Such nodules often form around an organic nucleus, such as decaying plant roots or microbes, which triggers local mineral deposition.
Field identification & locations
Identified by its crumbly, powdery texture, earthy smell when wetted, and tendency to disintegrate in water; ubiquitous in clay-rich soils.
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