sedimentary

River gravel and cobbles

Mixed alluvial clasts, likely including granite, basalt, quartzite, and sandstone

AI-generated identification · may be incorrect

Rounded to subrounded pebbles and cobbles with varied gray, brown, and reddish colors; generally hard (about Mohs 6–7), dull to vitreous luster, and no single crystal structure or cleavage because this is a mixed aggregate.

Identified August 17, 2026More sedimentary →

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Physical properties

Formation & geological history

These are sedimentary deposits formed when flowing water eroded, transported, and rounded older rocks; the exact geological ages vary from ancient source rocks to young modern stream deposits.

Uses & applications

Used for landscaping, drainage, paths, concrete aggregate, and erosion control; individual attractive stones may have minor decorative or collecting value.

Geological facts

The image shows a child beside a landscaped or natural-looking bed of rounded river stones, not one identifiable specimen.

Field identification & locations

Identify them by rounded shapes, mixed lithologies, and water-worn surfaces; common along rivers, beaches, glacial outwash, and landscaping sites. Individual stones require close inspection for a precise identification.