sedimentary
River Pebble
Weathered Sedimentary Rock Fragment
Hardness varies between 5 and 7 on the Mohs scale depending on mineral composition; colors range from gray to brown; dull to sub-vitreous luster; cryptocrystalline or clastic structure; lacks distinct cleavage due to rounding.
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Physical properties
Hardness varies between 5 and 7 on the Mohs scale depending on mineral composition; colors range from gray to brown; dull to sub-vitreous luster; cryptocrystalline or clastic structure; lacks distinct cleavage due to rounding.
Formation & geological history
Formed through the weathering and erosion of parent rock masses, followed by transport and mechanical rounding via water action in rivers or streams over thousands to millions of years.
Uses & applications
Used primarily in landscaping, garden decoration, aquarium substrates, and civil engineering projects.
Geological facts
The smooth, rounded shape of river pebbles is caused by abrasion as water tumbles them against other rocks along the riverbed.
Field identification & locations
Found abundantly in and around riverbeds, lake shores, and alluvial deposits worldwide. Identify by smooth, water-worn surfaces and rounded edges.
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