sedimentary
Common River Rock
Siliceous rock fragment
AI-generated identification · may be incorrectHardness varies from 6 to 7 on the Mohs scale depending on quartz content. Typically brown, grey, or tan with a smooth, water-worn texture and dull luster.
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Physical properties
Hardness varies from 6 to 7 on the Mohs scale depending on quartz content. Typically brown, grey, or tan with a smooth, water-worn texture and dull luster.
Formation & geological history
Formed through the mechanical weathering and fluvial transport of parent rocks over thousands to millions of years.
Uses & applications
Widely used in landscaping, gardening, decorative pathways, and as aggregate in construction.
Geological facts
Water-worn pebbles and cobbles develop their rounded shapes as tumbling river currents grind them against other stones.
Field identification & locations
Found abundantly in riverbeds, streams, and beaches worldwide; identified by smooth rounded edges and high resistance to weathering.
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