sedimentary

Rounded gray river pebble

Indeterminate; likely weathered basalt, andesite, or fine-grained graywacke

AI-generated identification · may be incorrect

Dark gray-brown, smooth and water-worn, with a dull to faintly glassy luster and no visible crystals or cleavage. Estimated hardness 5–7 Mohs; density likely about 2.6–3.0 g/cm³, but exact identification requires a streak, hardness, and acid test.

Identified August 22, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from an older rock and rounded by abrasion in a river, beach, or glacial environment; its original geological age cannot be determined visually. The smooth surface indicates substantial transport and weathering.

Uses & applications

Usually collected as a natural pebble, landscaping stone, or craft material; typically unsuitable for jewelry unless it has attractive color or internal pattern.

Geological facts

The specimen is too visually uniform and low-resolution for confident mineral or rock identification. A magnet test, fresh-edge inspection, and examination of grain size would help distinguish basalt from sedimentary alternatives.

Field identification & locations

Common in streambeds, beaches, and glacial deposits worldwide; look for fine grain, dense weight, and possible tiny feldspar crystals if basaltic. Collector value is generally minimal.