sedimentary

Sandstone Pebble (River Cobble)

Arenite (Sandstone)

AI-generated identification · may be incorrect

Hardness: 6-7 on Mohs scale; Color: Greyish-brown to tan; Luster: Dull/earthy; Texture: Fine-grained, gritty to the touch, well-rounded by stream action

Hardness: 6-7 on Mohs scale
Color: Greyish-brown to tan
Luster: Dull/earthy

Identified July 25, 2026More sedimentary →

Explore Sandstone Pebble (River Cobble) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6-7 on Mohs scale; Color: Greyish-brown to tan; Luster: Dull/earthy; Texture: Fine-grained, gritty to the touch, well-rounded by stream action

Formation & geological history

Formed by the accumulation and cementation of sand-sized mineral particles (mostly quartz and feldspar) in fluvial or marine environments. This specific piece has undergone mechanical weathering and stream transport, smoothing its edges.

Uses & applications

Used in construction, landcaping, decorative gardens, aquariums, and road sub-base material. Common as everyday pebbles or stones.

Geological facts

Stream-rounded rocks like this are often referred to as river stones or cobbles. Over thousands of years, water currents tumble these rocks against each other, grinding away sharp edges.

Field identification & locations

Identified by its sandy, gritty texture, uniform brownish-grey color, and smooth rounded shape resulting from stream erosion. Commonly found in riverbeds, beaches, and glacial till worldwide.