Red Sandstone

Physical Properties

Hardness: 6-7 Mohs; Color: reddish-brown due to iron oxide (hematite); Luster: dull/earthy; Crystal structure: clastic texture with sand-sized grains; Cleavage: none; Specific gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments, typically in desert, river, or ocean environments. The red color indicates formation in an oxygen-rich environment where iron minerals oxidized.

Uses & Applications

Widely used in construction as a building stone (flagstone), for decorative landscaping, and historically for statues and monuments.

Geological Facts

The famous red rocks of Sedona, Arizona and the Grand Canyon are iconic examples of massive sandstone formations. It is a primary reservoir rock for groundwater and petroleum.

Field Identification & Locations

Identified by its gritty sandpaper-like feel and visible grains. Often found in areas with historical riverbeds or dunes. Check for bedding planes and use a magnifying glass to see individual grains.

Identified on: 5/20/2026

Mode: Standard