sedimentary

Red Sandstone

Arenite (predominantly SiO2 with Fe2O3)

AI-generated identification · may be incorrect

Hardness: 6-7 on Mohs scale; Color: Reddish-brown due to iron oxide staining; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific gravity: 2.2-2.8

Hardness: 6-7 on Mohs scale
Color: Reddish-brown due to iron oxide staining
Luster: Dull/Earthy

Identified March 30, 2026More sedimentary →

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Physical properties

Hardness: 6-7 on Mohs scale; Color: Reddish-brown due to iron oxide staining; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific gravity: 2.2-2.8

Formation & geological history

Formed through the accumulation, compaction, and lithification of sand-sized mineral grains or rock fragments. The red color suggests deposition in an arid or highly oxygenated terrestrial environment like a desert or river bed where iron oxidized. Typical ages range from Proterozoic to Cenozoic.

Uses & applications

Extensively used in construction as a building stone (brownstone), paving slabs, and as a raw material for glass manufacturing if purity is high. Also used in decor and aquascaping.

Geological facts

Red sandstone is responsible for some of the world's most famous geological landmarks, including the 'Red Rocks' of Colorado, the Grand Canyon walls, and the Petra archaeological site in Jordan.

Field identification & locations

Identify in the field by its gritty, sandpaper-like texture and visible sand grains. It is commonly found in sedimentary basins and arid plateaus globally. Collectors look for unique banding or fossil inclusions.