sedimentary/metamorphic

Rounded river pebble, likely quartz-rich sandstone or quartzite

Indeterminate quartz-rich clast; predominantly SiO₂

AI-generated identification · may be incorrect

Smooth, water-worn, pale tan-gray, dull to weakly waxy luster, and fine-grained texture; likely hardness about 6–7 Mohs with no visible cleavage. The image is insufficient to distinguish sandstone from quartzite confidently.

Identified August 8, 2026More sedimentary/metamorphic →

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Physical properties

Formation & geological history

Formed from quartz-rich sediment cemented into sandstone, or metamorphosed into quartzite, then weathered and rounded by stream or beach transport. Its geological age cannot be determined visually.

Uses & applications

Typically used as landscaping or decorative stone; specimens of this ordinary appearance have little commercial or jewelry value.

Geological facts

The rounded shape and surface smoothing indicate prolonged abrasion by moving water or sediment. A glassy scratch test and visible sand grains can help separate quartzite from sandstone.

Field identification & locations

Common in streambeds, beaches, gravel bars, and glacial deposits worldwide. A steel nail should not scratch quartzite; sandstone may show individual grains and can feel slightly gritty, while acid testing is generally uninformative.