sedimentary
River Rock
Polished Siliceous Rock / Quartzite Pebble
Hardness varies from 6 to 7 on the Mohs scale depending on mineral content; color is dark greenish-brown with a smooth, rounded surface; luster ranges from dull to vitreous when wet; amorphous crystal structure due to weathering.
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Physical properties
Hardness varies from 6 to 7 on the Mohs scale depending on mineral content; color is dark greenish-brown with a smooth, rounded surface; luster ranges from dull to vitreous when wet; amorphous crystal structure due to weathering.
Formation & geological history
Formed through the continuous mechanical weathering, abrasion, and fluvial transport of parent rocks in riverbeds or coastal environments over thousands to millions of years.
Uses & applications
Used primarily in landscaping, garden decoration, aquariums, and construction aggregate.
Geological facts
Water-worn stones like this are smoothed by the natural tumbling action of water and sediment, a process that breaks away softer minerals and sharp edges over long distances.
Field identification & locations
Easily identified by its smooth, water-worn shape and rounded contours. Commonly found in riverbeds, lake shores, and glacial till deposits worldwide.
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