sedimentary

Red Sandstone

Arenite (with Iron Oxide)

Hardness: 6-7 Mohs; Color: reddish-brown to terracotta; Luster: dull/earthy; Crystal structure: clastic/granular; Cleavage: none; Specific gravity: 2.2-2.8

Hardness: 6-7 Mohs
Color: reddish-brown to terracotta
Luster: dull/earthy

Identified July 15, 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 Mohs; Color: reddish-brown to terracotta; Luster: dull/earthy; Crystal structure: clastic/granular; Cleavage: none; Specific gravity: 2.2-2.8

Formation & geological history

Formed through the accumulation and cementation of sand-sized mineral grains, primarily quartz. The red color is caused by the oxidation of iron minerals (hematite) during the lithification process, common in arid, terrestrial environments like deserts or river basins.

Uses & applications

Used extensively in construction as dimension stone, paving, and decorative garden stone. Often crushed for industrial sand or used in lapidary work for carving.

Geological facts

Famous formations include the Red Rocks of Colorado and the sandstone buttes of Monument Valley. It is a major aquifer rock due to its high porosity.

Field identification & locations

Identifiable by its gritty, sandpaper-like texture and visible sand grains. Found globally in continental sedimentary basins. Collectors look for unique weathering patterns or fossils embedded within.