sedimentary

Pebble

Lithified rock fragment / Sedimentary clast

AI-generated identification · may be incorrect

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.

Identified July 29, 2026More sedimentary →

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Physical properties

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.