sedimentary

Red Sandstone

Ferruginous Sandstone (formula varies, primarily SiO2 with Fe2O3)

AI-generated identification · may be incorrect

Hardness: 6-7 on Mohs scale; Color: Reddish-brown to brick red; Luster: Dull or earthy; Crystal structure: Clastic texture with sand-sized grains; Cleavage: None; Specific gravity: 2.2 to 2.8.

Hardness: 6-7 on Mohs scale
Color: Reddish-brown to brick red
Luster: Dull or earthy

Identified June 27, 2026More sedimentary →

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Physical properties

Hardness: 6-7 on Mohs scale; Color: Reddish-brown to brick red; Luster: Dull or earthy; Crystal structure: Clastic texture with sand-sized grains; Cleavage: None; Specific gravity: 2.2 to 2.8.

Formation & geological history

Formed by the accumulation and cementation of sand-sized grains of mineral or rock fragments. The red color is due to the presence of iron oxides (hematite) during the lithification process, often in arid or continental environments.

Uses & applications

Widely used as a construction material for building facades, paving, and monuments. It is also popular in landscaping and as a decorative stone.

Geological facts

Red sandstone is famous for creating iconic geological features like the Red Rocks Amphitheatre in Colorado and the 'Old Red Sandstone' formations in Great Britain which helped James Hutton develop the theory of uniformitarianism.

Field identification & locations

Identify by its gritty texture (feels like sandpaper) and distinct red/brown staining that does not wash off. Found in desert environments or ancient river beds. Collectors look for unique banding or fossil inclusions.