mineral
Worn quartz-rich pebble
Likely microcrystalline quartz (SiO₂), possibly a weathered chert or milky quartz fragment
AI-generated identification · may be incorrectPale gray-beige, opaque to slightly translucent, with a dull-to-waxy luster and rounded abrasion surfaces; quartz hardness is about 7 Mohs, with no obvious cleavage and conchoidal fracture. Exact identification is limited by the photograph.
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Physical properties
Pale gray-beige, opaque to slightly translucent, with a dull-to-waxy luster and rounded abrasion surfaces; quartz hardness is about 7 Mohs, with no obvious cleavage and conchoidal fracture. Exact identification is limited by the photograph.
Formation & geological history
Likely formed in silica-rich igneous or sedimentary material and later rounded by stream, beach, or soil abrasion; its geological age cannot be determined visually. If chert, it formed from silica-rich sediment or biogenic ooze that lithified and recrystallized.
Uses & applications
Common pieces have little commercial value, but quartz and chert are used for glass, ceramics, abrasives, aggregate, and historically tools; attractive specimens may be used as curios or craft material.
Geological facts
A steel nail should not easily scratch quartz, while quartz can scratch ordinary glass. The diffuse, fine-grained appearance may indicate chert rather than a single quartz crystal.
Field identification & locations
Commonly found in stream gravels, beaches, soils, and quartz-bearing bedrock worldwide. Test hardness, inspect for conchoidal fracture, and use a loupe or streak test; laboratory testing is needed for certainty.
