sedimentary

Rounded river pebble, likely quartz-rich sandstone or weathered quartzite

Indeterminate; probable quartz (SiO₂)-rich clastic rock

AI-generated identification · may be incorrect

Brown to reddish-brown, dull to weakly sparkling surface, fine-grained and well-rounded; likely hardness about 6–7 if quartz-rich, with no obvious cleavage. Exact texture and mineralogy cannot be confirmed from the photograph alone.

Identified August 16, 2026More sedimentary →

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Physical properties

Formation & geological history

Shaped by prolonged abrasion in a stream, beach, or glacial environment; the original sandstone may have formed from compacted sand millions to hundreds of millions of years ago, while quartzite would be metamorphosed sandstone.

Uses & applications

Usually valued as a decorative or educational specimen; similar material may be used as aggregate, landscaping stone, or limited lapidary material if it takes a polish.

Geological facts

The smooth, flattened form indicates transport and abrasion rather than crystal growth. Surface patches may be weathering, iron-oxide staining, or minor mica/mineral grains.

Field identification & locations

Common in river gravels and shorelines. Scratch-testing an inconspicuous area with steel or glass, examining a fresh break with a hand lens, and checking for visible sand grains can distinguish sandstone from quartzite; avoid destructive tests on collectible pieces.