sedimentary

Rounded river pebbles

Unidentified mixed lithologies; the reddish pebble may be iron-stained sandstone or volcanic rock

AI-generated identification · may be incorrect

Pebble-sized, water-worn stones with dull to slightly earthy luster; visible colors include red-brown, gray-green, and dark gray. Hardness, mineral content, and crystal structure cannot be determined reliably from the image.

Identified October 13, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from older rocks and rounded by abrasion in a river or on a beach; their geological ages and exact formation histories are unknown.

Uses & applications

Commonly used for landscaping, crafts, aquariums, and collecting; these small, unclassified specimens have little commercial value.

Geological facts

The smooth, rounded shapes indicate prolonged transport or wave action, but color alone is insufficient to identify the rock types.

Field identification & locations

Look for grain size, layering, crystals, and reaction to a scratch or dilute acid to narrow identification. Similar pebbles occur in riverbeds and coastal deposits worldwide.