sedimentary
Pebble
Lithified rock fragment / Sedimentary clast
Hardness varies greatly depending on mineral composition (typically 5-7 on the Mohs scale for quartz-rich pebbles); Color ranges from grey, green, brown to multicolored; Luster is dull to sub-vitreous; Structure is amorphous/clastic due to water tumbling.
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Physical properties
Hardness varies greatly depending on mineral composition (typically 5-7 on the Mohs scale for quartz-rich pebbles); Color ranges from grey, green, brown to multicolored; Luster is dull to sub-vitreous; Structure is amorphous/clastic due to water tumbling.
Formation & geological history
Formed through the mechanical weathering and erosion of larger parent rocks, followed by prolonged transport and water abrasion in rivers, streams, or beach environments.
Uses & applications
Used in landscaping, gardening, aquarium decoration, and as a raw aggregate in construction.
Geological facts
Pebbles are classified by geologists based on their grain size using the Wentworth scale, specifically particles measuring between 4 to 64 millimeters in diameter.
Field identification & locations
Found abundantly in riverbeds, lake shores, and beaches worldwide. Identification relies on observing rounded, water-worn shapes and testing hardness.
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