Red Sandstone

Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)

Rock Type: sedimentary

Red Sandstone

Physical Properties

Hardness: 6-7 (Mohs scale), Color: Reddish-brown to rust-red, Luster: Dull/Earthy, Crystal Structure: Granular/Clastic, 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. The red color indicates formation in an oxygen-rich environment where iron minerals have oxidized (rusted).

Uses & Applications

Widely used in construction for building stone, pavers, and decorative landscaping. High-quality varieties are used for grindstones and sculpture.

Geological Facts

The vibrant red color of many famous landscapes, such as the Grand Canyon and the red rocks of Sedona, is due to the presence of oxidized iron in sandstone layers.

Field Identification & Locations

Identify by its gritty, sandpaper-like texture and visible sand grains. It is often found in desert environments, river beds, and coastal areas. Collectors should look for unique layering or cross-bedding features.

Identified on: 4/13/2026

Mode: Standard