igneous
River Pebble (Granite/Sandstone Pebble)
Rounded Quartz/Feldspar Gravel Clast
Mohs hardness around 6-7, light grey to tan color with a speckled, granular texture, dull to earthy luster, rounded oval shape due to stream or wave action, non-porous to slightly porous.
Identified More igneous →
Explore River Pebble (Granite/Sandstone Pebble) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness around 6-7, light grey to tan color with a speckled, granular texture, dull to earthy luster, rounded oval shape due to stream or wave action, non-porous to slightly porous.
Formation & geological history
Formed through mechanical weathering and erosion of larger igneous or sedimentary rock formations. Transported and rounded over time by water currents in streams, rivers, or beach environments.
Uses & applications
Commonly used as construction aggregate, decorative landscaping gravel, driveway cover, and in concrete manufacturing. Small smooth stones are often used for crafts or garden decoration.
Geological facts
Smooth river stones acquire their rounded, egg-like shapes through abrasion against other rocks during river transport over hundreds to thousands of years.
Field identification & locations
Identified by its smooth, egg-shaped, rounded contours and uniform granular surface resulting from water erosion. Extremely common worldwide in riverbeds, gravel pits, and coastal areas.
