Red Sandstone

Physical Properties

Hardness: 6-7 (Mohs scale for individual quartz grains); Color: reddish-brown, maroon, or tan; Luster: matte/earthy; Crystal structure: granular clastic texture; Cleavage: none; Specific gravity: 2.2–2.8

Formation & Geological History

Formed through the accumulation and cementation of sand-sized grains, typically in arid desert environments (eolian) or riverbeds (fluvial). Its red color is derived from iron oxide (hematite) coating the grains, often dating back to the Paleozoic or Mesozoic eras.

Uses & Applications

Used extensively as a building material, pavers, decorative landscaping stone, and architectural facades. Historically used for grinding stones and monuments.

Geological Facts

Red sandstone is famous for creating the iconic landscapes of the American Southwest, such as the Grand Canyon and Sedona's Red Rocks. It often preserves cross-bedding patterns from ancient sand dunes.

Field Identification & Locations

Identify by its gritty, sandpaper-like feel and visible small grains. Found in large sedimentary basins globally, such as the Colorado Plateau or the Old Red Sandstone of Great Britain. It will not fizz with acid unless it contains calcite cement.

Identified on: 4/22/2026

Mode: Standard