sedimentary

Red sandstone

Iron-oxide–stained quartz arenite, likely Navajo or Aztec Sandstone

AI-generated identification · may be incorrect

Usually 90–100% quartz with minor feldspar, clay, and hematite; Mohs hardness about 6–7 for quartz grains, reddish-orange color, dull to slightly gritty luster, porous, and commonly displays prominent cross-bedding and layered weathering.

Identified September 1, 2026More sedimentary →

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Physical properties

Formation & geological history

Lithified wind-blown sand dunes in an ancient desert, cemented mainly by silica or iron oxides; formations of this type commonly date from the Jurassic Period, roughly 180–150 million years ago.

Uses & applications

Crushed sandstone is used for aggregate, fill, and building stone; attractive slabs and blocks are used decoratively, though friable varieties have limited durability. Natural outcrops are especially valued for scenery and geology education.

Geological facts

The red color comes chiefly from hematite coatings on quartz grains. Large-scale cross-bedding records migrating ancient dunes and prevailing wind directions.

Field identification & locations

Common in the Colorado Plateau, including southern Utah, northern Arizona, Nevada, and Colorado. Identify it by gritty quartz texture, red iron staining, visible bedding or cross-bedding, and sedimentary layering; the exact formation cannot be confirmed from one photograph.