Red Sandstone

Physical Properties

Hardness: 6-7 (on Mohs scale); Color: Red, reddish-brown, or orange; Luster: Dull/Earthy; Crystal structure: Clastic (grain-based); Cleavage: None; Specific Gravity: 2.2–2.8

Formation & Geological History

Formed through the accumulation and lithification of sand-sized mineral particles. The red color is caused by the oxidation of iron minerals (hematite) during or after deposition in arid continental environments, often during the Permian or Triassic periods.

Uses & Applications

Used extensively as a building material (brownstone), flagstone for landscaping, decorative garden stones, and as a reservoir rock for oil and natural gas.

Geological Facts

Red sandstone formations like those in the American Southwest (e.g., Antelope Canyon, Sedona) are iconic. Many famous historic buildings in the UK and Northeastern US are constructed from 'Old Red Sandstone'.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and visible layers or bedding planes. It can be found globally, particularly in areas like the Colorado Plateau or the Scottish Highlands.

Identified on: 4/19/2026

Mode: Standard