sedimentary

Red sandstone

Quartz-rich sandstone, commonly iron-oxide-cemented (SiO₂ with hematite/goethite)

AI-generated identification · may be incorrect

Reddish, dull and visibly granular; composed mainly of quartz, with variable feldspar and iron oxides. Quartz grains are Mohs 7, but the rock’s hardness and durability depend on cementation; crystals are too small to show cleavage.

Identified October 14, 2026More sedimentary →

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Physical properties

Formation & geological history

Sand accumulated and was compacted and cemented in ancient river, dune, or desert settings; iron oxides impart the red color. Its age cannot be determined from the image.

Uses & applications

Used as building and paving stone, aggregate, and decorative landscaping material; attractive pieces may be collected.

Geological facts

Red sandstone’s color commonly comes from iron-oxide coatings on grains or cement between them.

Field identification & locations

Look for gritty texture, visible sand-sized grains, and reddish coloration; it is widespread in sedimentary basins worldwide. The exposed piece appears naturally weathered, with no scale or location to identify its formation more precisely.