mineral
Kaolinite (clay mineral)
Kaolinite, Al₂Si₂O₅(OH)₄
AI-generated identification · may be incorrectTypically white to cream with a dull-to-pearly luster and earthy, layered appearance; hardness about 2–2.5 Mohs, perfect basal cleavage, triclinic crystal structure, and specific gravity around 2.6. The specimen’s pale color and flaky, compact texture are consistent with kaolinite.
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Physical properties
Typically white to cream with a dull-to-pearly luster and earthy, layered appearance; hardness about 2–2.5 Mohs, perfect basal cleavage, triclinic crystal structure, and specific gravity around 2.6. The specimen’s pale color and flaky, compact texture are consistent with kaolinite.
Formation & geological history
Forms mainly by chemical weathering or hydrothermal alteration of feldspar-rich rocks, commonly in warm, humid environments; deposits range from ancient to recent. It often occurs with quartz and other clay minerals.
Uses & applications
Used in porcelain and ceramics, paper coating and filler, paints, rubber, and cosmetics; attractive specimens may be collected, though kaolinite is not generally a gemstone.
Geological facts
Kaolinite is the principal mineral in kaolin, or “china clay,” historically important in fine porcelain manufacture.
Field identification & locations
Look for soft, pale, earthy material that can feel smooth or slightly soapy and leaves a white streak; common deposits occur in China, England, Brazil, and the southeastern United States. A photo alone cannot confirm the mineral identification.
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