sedimentary
River Rock
Siliceous water-worn rock
AI-generated identification · may be incorrectHardness varies from 6 to 7 on the Mohs scale, typically brown or gray, dull luster, amorphous or cryptocrystalline structure, smooth water-worn surface.
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Physical properties
Hardness varies from 6 to 7 on the Mohs scale, typically brown or gray, dull luster, amorphous or cryptocrystalline structure, smooth water-worn surface.
Formation & geological history
Formed through the mechanical weathering, erosion, and long-term water transport of parent rocks in riverbeds over thousands to millions of years.
Uses & applications
Used widely in landscaping, gardening, decorative gravel, and construction aggregates.
Geological facts
Continuous abrasion in fast-flowing water rounds sharp edges, creating the characteristic smooth pebble shape.
Field identification & locations
Found abundantly in and around riverbeds, stream banks, and ancient alluvial deposits worldwide. Identify by smooth, rounded morphology.
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