sedimentary

Sandstone Cobble

Arenite (Secondary classification based on grain size)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale); Color: Tan, brownish-yellow, buff; Luster: Dull/Earthy; Crystal structure: Clastic (sand grains); Cleavage: None/Irregular fracture; Specific gravity: 2.1-2.8

Hardness: 6-7 (Mohs scale)
Color: Tan, brownish-yellow, buff
Luster: Dull/Earthy

Identified April 6, 2026More sedimentary →

Explore Sandstone 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 (Mohs scale); Color: Tan, brownish-yellow, buff; Luster: Dull/Earthy; Crystal structure: Clastic (sand grains); Cleavage: None/Irregular fracture; Specific gravity: 2.1-2.8

Formation & geological history

Formed over millions of years from the accumulation of sand-sized mineral particles or rock fragments, cemented together by silica, calcium carbonate, or iron oxide. This specific piece shows significant rounding from water transport in a river or glacial environment.

Uses & applications

Used primarily in construction as a building material, road base, and as a source for glass-making silica if pure.

Geological facts

Sandstone represents about 20-25% of all sedimentary rocks on Earth. The rounded edges of this specific specimen suggest it was a river rock or 'cobble' transported long distances.