Sandstone

Physical Properties

Hardness: 6-7 (Mohs scale), Color: Tan, brown, or reddish-brown, Luster: Dull/Earthy, Crystal structure: Granular/Clastic, Cleavage: None, Specific Gravity: 2.2-2.8

Formation & Geological History

Formed by the accumulation and lithification of sand-sized mineral particles or rock fragments, typically in river beds, oceans, or deserts, over millions of years.

Uses & Applications

Extensively used as a building material, in paving, for decorative garden stones, and as a source of silica for glass manufacturing.

Geological Facts

Sandstone can be found in almost every geological age from Precambrian to Quaternary. It often preserves fossils and ripple marks from ancient water currents.

Field Identification & Locations

Identified by its gritty, sandpaper-like feel and visible grain structure. Commonly found in canyons, beaches, and desert plateaus. Collectors should look for layering or fossil inclusions.

Identified on: 5/17/2026

Mode: Standard