sedimentary

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

AI-generated identification · may be incorrect

Hardness: 6-7 Mohs; Color: Tan, yellow, reddish-brown due to iron oxidation; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8

Hardness: 6-7 Mohs
Color: Tan, yellow, reddish-brown due to iron oxidation
Luster: Dull/Earthy

Identified June 5, 2026More sedimentary →

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Physical properties

Hardness: 6-7 Mohs; Color: Tan, yellow, reddish-brown due to iron oxidation; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8

Formation & geological history

Formed through the accumulation and cementation of sand-sized silicate grains (mostly quartz). This specific specimen shows heavy iron oxide staining (limonite/hematite), common in terrestrial or shallow marine environments from the Paleozoic to Cenozoic eras.

Uses & applications

Commonly used as a building material, in decorative masonry, as an abrasive, and sometimes as a reservoir rock for oil and gas.

Geological facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. The color variations are often caused by the type of mineral 'glue' or matrix holding the sand grains together.

Field identification & locations

Identify in the field by its gritty 'sandpaper' feel and visible layers or bedding. It is ubiquitous in arid regions and canyon landscapes worldwide, such as the American Southwest.