sedimentary

Red sandstone

Iron-oxide-stained quartz sandstone; exact mineral composition cannot be confirmed from the image

AI-generated identification · may be incorrect

Reddish-brown, dull and visibly granular with a rough, uneven fracture. Sandstone commonly has Mohs hardness around 6–7 for its quartz grains, but cement strength varies; quartz is trigonal.

Identified October 9, 2026More sedimentary →

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Physical properties

Reddish-brown, dull and visibly granular with a rough, uneven fracture. Sandstone commonly has Mohs hardness around 6–7 for its quartz grains, but cement strength varies; quartz is trigonal.

Formation & geological history

Formed when sand grains—often quartz—were compacted and cemented, with iron oxides producing the red color. Sandstones form in settings such as rivers, deserts, and shorelines; this specimen’s age and specific origin are unknown.

Uses & applications

Used as building and paving stone, and sometimes for landscaping or decorative objects; this rough fragment has little jewelry use.

Geological facts

Red coloration commonly results from hematite or other iron-oxide coatings on grains or cement.

Field identification & locations

Look for gritty grains and layered texture; a quartz-rich specimen can scratch glass, though cement may crumble. Red sandstones occur worldwide, including the southwestern United States and many ancient sedimentary basins.