sedimentary

Red Sandstone

Arenite (Ferruginous Sandstone)

Hardness: 6-7 on Mohs scale; Color: Reddish-brown, orange, tan; Luster: Dull, earthy; Crystal structure: Clastic (sand grains); Cleavage: None; Specific gravity: 2.2-2.8

Hardness: 6-7 on Mohs scale
Color: Reddish-brown, orange, tan
Luster: Dull, earthy

Identified July 14, 2026More sedimentary →

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Physical properties

Hardness: 6-7 on Mohs scale; Color: Reddish-brown, orange, tan; Luster: Dull, earthy; Crystal structure: Clastic (sand grains); Cleavage: None; Specific gravity: 2.2-2.8

Formation & geological history

Formed by the accumulation and lithification of sand-sized mineral particles or rock fragments. The red color indicates the presence of iron oxide (hematite) which coated the grains during deposition in oxygen-rich environments like deserts or river beds.

Uses & applications

Commonly used in construction as a building material, and for decorative masonry. Historically significant in architecture for various ancient monuments and cathedrals.

Geological facts

The red color is essentially 'rusting' of the iron minerals within the sand. Famous formations include the Grand Canyon and the Red Rocks of Sedona.

Field identification & locations

Identify in the field by its gritty, sandpaper-like texture and visible sand grains. It is extremely common in arid environments and sedimentary basins globally.