sedimentary

Sandstone

Arenite (SiO2 based)

Hardness: 6-7 (Mohs scale); Color: Brown, tan, reddish-brown; Luster: Dull/Earthy; Crystal structure: Clastic/Granular; Cleavage: None; Specific gravity: 2.2-2.8

Hardness: 6-7 (Mohs scale)
Color: Brown, tan, reddish-brown
Luster: Dull/Earthy

Identified May 16, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale); Color: Brown, tan, reddish-brown; Luster: Dull/Earthy; Crystal structure: Clastic/Granular; Cleavage: None; Specific gravity: 2.2-2.8

Formation & geological history

Formed from the accumulation of sand-sized grains (mostly quartz and feldspar) in environments like deserts, river beds, or beaches. Over millions of years, pressure and minerals cement the grains into rock.

Uses & applications

Used extensively in construction as a building material, paving stone, and for decorative masonry. It is also an important reservoir rock for oil, gas, and groundwater.

Geological facts

Sandstone makes up about 20-25% of all sedimentary rocks on Earth. The iconic red rocks of the American Southwest, such as those in the Grand Canyon, are primarily composed of sandstone layers.

Field identification & locations

Identify by its gritty, sandpaper-like feel and visible grains. Often displays visible layering or bedding. Commonly found in outcroppings near ancient water bodies or desert regions.