sedimentary
River Rock
Silica-rich water-worn rock
Hardness varies from 6 to 7 on the Mohs scale depending on mineral content, typically quartz-dominant; color ranges from tan, brown, to grey with organic green algae patches; luster is dull to sub-vitreous; smooth, rounded texture due to water erosion.
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Physical properties
Hardness varies from 6 to 7 on the Mohs scale depending on mineral content, typically quartz-dominant; color ranges from tan, brown, to grey with organic green algae patches; luster is dull to sub-vitreous; smooth, rounded texture due to water erosion.
Formation & geological history
Formed through mechanical weathering and prolonged aqueous transport, where rough stones are smoothed by abrasion in rivers, streams, or glacial environments over thousands to millions of years.
Uses & applications
Widely used in landscaping, garden decoration, construction, and sometimes in interior design.
Geological facts
River rocks are naturally tumbled by water currents, making them smoother and more rounded than freshly fractured rocks found in quarry settings.
Field identification & locations
Easily identified by their smooth, water-worn exterior and rounded shape, commonly found in riverbeds, lake shores, and glacial outwash plains.
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