sedimentary
Pebbles
Polymictic rock fragments
Hardness varies (generally 6-7 on Mohs scale due to quartz content), colors range from tan to speckled grey, vitreous to dull luster, amorphous or cryptocrystalline structure, smooth water-worn texture.
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Physical properties
Hardness varies (generally 6-7 on Mohs scale due to quartz content), colors range from tan to speckled grey, vitreous to dull luster, amorphous or cryptocrystalline structure, smooth water-worn texture.
Formation & geological history
Formed by weathering, erosion, and transport of various parent rocks by water in rivers, streams, or coastal environments over varying geological timescales.
Uses & applications
Used in landscaping, decorative ground cover, garden pathways, and sometimes in concrete aggregate or drainage systems.
Geological facts
River pebbles become smooth and rounded through a process called abrasion, as they collide with other rocks and sand particles while being transported by water currents.
Field identification & locations
Found globally in riverbeds, lake shores, and beaches; helpful for geologists in determining the provenance and transport history of local sediment deposits.
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