sedimentary
River Rock
Siliciclastic rock (water-worn pebble)
Hardness varies from 6 to 7 on the Mohs scale depending on mineral content (mostly quartz); color is typically dark green, brown, or gray; luster is dull to sub-vitreous; smooth, rounded texture due to water abrasion.
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Physical properties
Hardness varies from 6 to 7 on the Mohs scale depending on mineral content (mostly quartz); color is typically dark green, brown, or gray; luster is dull to sub-vitreous; smooth, rounded texture due to water abrasion.
Formation & geological history
Formed through the weathering and erosion of larger rock formations, followed by long-term transportation and abrasion in riverbeds or coastal environments.
Uses & applications
Used in landscaping, decorative garden stones, construction, and rock tumbling or crafting.
Geological facts
The smooth, rounded shape is created by natural tumbling as water carries the rock downstream, causing it to collide with other sediments over thousands to millions of years.
Field identification & locations
Commonly found along riverbanks, lake shores, and stream beds worldwide. Identified by its rounded shape and smooth surface.
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