metamorphic
Biotite-rich schist (probable)
Mica schist, likely biotite–quartz–feldspar schist
AI-generated identification · may be incorrectBrown-gray, coarse, glittering surface with visible mica flakes; likely Mohs 2.5–3 for biotite and 6–7 for quartz. Mica has platy crystals and one perfect cleavage; the specimen appears weakly foliated, though its exact minerals cannot be confirmed from the image.
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Physical properties
Brown-gray, coarse, glittering surface with visible mica flakes; likely Mohs 2.5–3 for biotite and 6–7 for quartz. Mica has platy crystals and one perfect cleavage; the specimen appears weakly foliated, though its exact minerals cannot be confirmed from the image.
Formation & geological history
Formed when clay-rich sediment or similar rock was buried and metamorphosed under heat and pressure, aligning mica grains into foliation. Its age and precise formation setting cannot be determined visually.
Uses & applications
Schist is used locally as building or landscaping stone and as a decorative dimension stone; mica-bearing specimens are mainly collected for display.
Geological facts
The sparkle comes from reflective mica flakes, while quartz and feldspar commonly make up much of the rock.
Field identification & locations
Look for mica glitter and a layered or foliated texture; common in metamorphic belts worldwide. The pictured rounded, weathered hand specimen is not diagnostic enough to establish its exact mineral composition.
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