sedimentary

Rounded river pebble, likely sandstone or weathered quartzite

Indeterminate lithic clast; probable quartz-rich sandstone (SiO₂-dominant)

AI-generated identification · may be incorrect

Tan-brown, smoothly water-worn, dull to slightly vitreous luster, with fine granular texture and possible iron-oxide staining. Estimated hardness 6–7 Mohs; cleavage absent and specific gravity roughly 2.6–2.7.

Identified August 26, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from cemented quartz-rich sediment, or possibly metamorphosed into quartzite, then rounded by stream or beach abrasion; its precise geological age cannot be determined from the image.

Uses & applications

Primarily a decorative or educational specimen; similar pebbles are used in landscaping, crafts, tumbling, and aggregate.

Geological facts

The rounded shape indicates prolonged transport or wave action. The darker patches may represent iron oxides, clay-rich areas, or natural surface staining rather than distinct minerals.

Field identification & locations

Common in riverbeds, beaches, and glacial deposits. Test with a steel file or glass: a quartz-rich pebble should scratch glass and resist a steel knife; dilute acid should produce no fizz.