sedimentary

Rounded quartz-rich river pebble

Likely quartz arenite or quartz-rich sandstone; exact identification requires testing

AI-generated identification · may be incorrect

Fine-grained, gray-brown, dull to slightly granular surface with rounded shape from abrasion; likely Mohs hardness about 6–7, quartz-dominated, with no obvious cleavage. Specific gravity approximately 2.6; weathered surface may obscure original texture.

Identified September 13, 2026More sedimentary →

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Physical properties

Formation & geological history

Probably a naturally cemented sandstone or quartz-rich sedimentary clast rounded in a river, beach, or glacial environment; the sediment may be hundreds of millions of years old, though its exact age cannot be determined visually.

Uses & applications

Generally used as a decorative stone, landscaping pebble, or educational specimen; not typically valuable for jewelry or construction in this small form.

Geological facts

The smooth oval form records prolonged transport and abrasion. A glass-scratch test or examination of a fresh fracture can help distinguish quartz-rich sandstone from fine-grained igneous rocks.

Field identification & locations

Common in streambeds, beaches, gravel deposits, and glacial till. Look for visible sand grains and weak layering; fizzing with dilute acid would indicate carbonate cement, while a hard scratch on glass supports abundant quartz.