sedimentary

Red Sandstone

Ferruginous Sandstone (SiO2 dominated with Fe2O3 cement)

Hardness: 6-7 (Mohs scale); Color: Reddish-brown, maroon, or tan due to iron oxides; Luster: Dull to earthy; Crystal structure: Clastic (composed of mineral grains); Cleavage: None; Specific gravity: 2.2-2.8.

Hardness: 6-7 (Mohs scale)
Color: Reddish-brown, maroon, or tan due to iron oxides
Luster: Dull to earthy

Identified March 20, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed by the accumulation of sand-sized mineral particles (usually quartz and feldspar) in desert, river, or coastal environments. The red color suggests deposition in an oxygen-rich environment where iron minerals oxidized. Geological ages vary, often associated with the Permian or Triassic periods.

Uses & applications

Commonly used in construction as a building material (dimension stone), flagstone for landscaping, and in aggregate for roads. Occasionally used in ornamental carvings.

Geological facts

Red sandstone is what gives famous landmarks like the Grand Canyon, Petra, and the Red Rocks Amphitheatre their iconic color. The 'red' is essentially rust (hematite) coating the translucent quartz grains.

Field identification & locations

Identify in the field by its gritty, sandpaper-like texture and visible layering (bedding planes). It is commonly found in the Southwestern United States, Scotland, and Central Europe. Collectors look for unique banding patterns or desert varnish.

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