sedimentary

Rounded gray-brown river pebble

Indeterminate lithic clast; likely weathered sandstone or fine-grained metamorphic rock

AI-generated identification · may be incorrect

Small, flattened and well-rounded, with a dull earthy luster and mottled gray, tan, and brown surface. Hardness appears approximately 5–7 Mohs, but mineral composition, cleavage, crystal structure, and specific gravity cannot be determined reliably from the image.

Identified August 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely formed as a fragment of older bedrock and rounded by prolonged stream or beach abrasion; its age is unknown and could range from millions to billions of years. Surface staining may reflect iron oxides or weathering.

Uses & applications

Primarily a natural collectible or decoration; it has no identifiable commercial or jewelry value without confirming composition and durability.

Geological facts

The smooth, flattened shape indicates transport and abrasion rather than a freshly broken rock surface. A fresh chip, hand lens, streak test, acid test, and hardness testing would improve identification.

Field identification & locations

Common in riverbeds, gravel bars, beaches, and glacial deposits. Check for visible grains, layering, foliation, acid reaction, and whether it scratches glass; avoid destructive tests on a potentially valuable specimen.