sedimentary

Sandstone

Arenite (SiO2 primarily)

Mohs hardness: 6 to 7; Color: Tan, yellow, or buff; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific gravity: 2.2 to 2.8.

Hardness: 6 to 7
Color: Tan, yellow, or buff
Luster: Dull/Earthy

Identified June 14, 2026More sedimentary →

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Physical properties

Mohs hardness: 6 to 7; Color: Tan, yellow, or buff; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific gravity: 2.2 to 2.8.

Formation & geological history

Formed through the accumulation and cementation of mineral particles or rock fragments (clasts) the size of sand. These typically deposit in river beds, beaches, or deserts. This example appears to be a weathered fluvial or desert deposit.

Uses & applications

Used extensively in construction as building stone, pavers, and grit for grinding tools. High-purity silica sandstone is used in glass making and hydraulic fracturing (frac sand).

Geological facts

Sandstone represents about 20 to 25 percent of all sedimentary rocks on Earth. It is porous and often acts as a massive natural filter for groundwater or a reservoir for petroleum and natural gas.

Field identification & locations

Identify by its 'sandpaper' feel. It will often show layering (bedding). Commonly found in sedimentary basins and canyonlands. Check for grain size and the presence of cements like calcite or silica.