metamorphic
Rounded quartz-rich pebble (likely quartzite or chert)
Quartzite, composed predominantly of microcrystalline quartz (SiO₂)
AI-generated identification · may be incorrectSmall, smooth, rounded pebble with cream-white and tan coloration, dull to weakly waxy luster, and no obvious cleavage. Quartz hardness is about Mohs 7; specific gravity is approximately 2.6, though the image is insufficient for definitive identification.
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Physical properties
Small, smooth, rounded pebble with cream-white and tan coloration, dull to weakly waxy luster, and no obvious cleavage. Quartz hardness is about Mohs 7; specific gravity is approximately 2.6, though the image is insufficient for definitive identification.
Formation & geological history
Likely formed as quartz-rich sediment lithified and metamorphosed into quartzite, then rounded by stream or beach abrasion; its exact geological age and source cannot be determined visually. A chert or ordinary quartz pebble is also possible.
Uses & applications
Commonly collected as a curiosity, used in landscaping and decorative gravel, and occasionally cut or polished for cabochons. This individual specimen has minimal commercial value.
Geological facts
Quartz-rich pebbles resist weathering and abrasion, allowing them to survive transport and become smoothly rounded. A glassy streak or visible interlocking quartz grains would support quartzite; a waxier texture suggests chert.
Field identification & locations
Common in riverbeds, beaches, glacial deposits, and gravel pits worldwide. Test hardness against glass and inspect a fresh surface; positive identification requires these tests or microscopy.
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