sedimentary

Rounded river pebble

Indeterminate; likely quartz-rich sandstone, chert, or weathered volcanic rock

AI-generated identification · may be incorrect

Small, naturally rounded, dull brown-gray pebble with a fine-grained texture and possible iron staining. Hardness and mineral composition cannot be determined reliably from the image; no obvious crystals or cleavage are visible.

Identified August 12, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely formed as a fragment of bedrock and rounded by prolonged transport in a river, beach, or gravel deposit. Its precise geological age and original rock type require testing or a fresh surface.

Uses & applications

Generally valued as a natural specimen, craft stone, or landscaping gravel rather than for industrial or jewelry use. A distinctive composition or provenance could increase collector interest.

Geological facts

The smooth shape indicates abrasion and repeated tumbling by moving water or sediment. A streak, hardness test, acid test, and close examination of a broken surface would help identify it.

Field identification & locations

Common in streambeds, beaches, glacial deposits, and construction gravel. Test whether it scratches glass, inspect grain size with a hand lens, and check for fizzing with dilute hydrochloric acid.