sedimentary

Red Sandstone

Arenite (Ferruginous Sandstone)

Hardness: 6-7 on Mohs scale; Color: Reddish-brown to maroon; 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 to maroon
Luster: Dull/Earthy

Identified July 9, 2026More sedimentary →

Explore Red Sandstone in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6-7 on Mohs scale; Color: Reddish-brown to maroon; Luster: Dull/Earthy; Crystal structure: Clastic (sand grains); Cleavage: None; Specific gravity: 2.2-2.8

Formation & geological history

Formed through the accumulation and cementation of sand-sized silicate grains (mostly quartz). The red color comes from iron oxide (hematite) coating the grains, typical of arid terrestrial environments or heavy oxidation over millions of years.

Uses & applications

Commonly used in construction for paving, building facades, and monuments. Also popular as decorative landscaping stone and for use in aquariums.

Geological facts

The famous red rock formations of Sedona, Arizona, and the Red Rocks Amphitheatre in Colorado are composed of this type of geological material. It often records ancient desert dune patterns.

Field identification & locations

Identify by its gritty, sandpaper-like feel and its distinct reddish hue. It is commonly found in sedimentary basins and plateaus. For collectors, look for cross-bedding layers which indicate ancient wind or water current directions.