sedimentary
River Pebble (Gravel Pebble)
Stream-rounded Rock / Siliciclastic Pebble
Hardness: 5-7 on Mohs scale depending on specific mineral composition (often quartz-rich). Color: Grey, brownish, dark olive-grey. Luster: Dull to sub-vitreous when dry, shiny when wet. Structure: Rounded to sub-angular shape from water abrasion.
- Color
- Grey, brownish, dark olive-grey
- Luster
- Dull to sub-vitreous when dry, shiny when wet
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Physical properties
Hardness: 5-7 on Mohs scale depending on specific mineral composition (often quartz-rich). Color: Grey, brownish, dark olive-grey. Luster: Dull to sub-vitreous when dry, shiny when wet. Structure: Rounded to sub-angular shape from water abrasion.
Formation & geological history
Formed through fluvial erosion where water action in rivers, streams, or coastal shores continuously breaks, rolls, and smooths rock fragments over years.
Uses & applications
Commonly used in construction aggregate, land-scaping, road bedding, concrete mixing, and decorative river rock beds.
Geological facts
Smooth river pebbles owe their soft, rounded edges to millions of collisions with other stones and sediment particles transported downstream by flowing water.
Field identification & locations
Identified by its rounded edges, smooth texture, and weathered surface. Found abundantly along riverbeds, stream channels, lake beaches, and gravel pits.
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