Sandstone (Ferruginous)

Physical Properties

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

Formation & Geological History

Formed from the accumulation and cementation of sand-sized mineral grains or rock fragments. The reddish hue indicates iron oxide (hematite) cementation in a fluvial or desert environment.

Uses & Applications

Used primarily in construction for paving, building stone, and decorative landscaping. Also used as a primary source for glass manufacturing if high in silica.

Geological Facts

Sandstone makes up about 20% to 25% of all sedimentary rocks on Earth. The famous 'Red Rocks' of the American Southwest are primarily ferruginous sandstones.

Field Identification & Locations

Identify in the field by its gritty, sandpaper-like texture and visible bedding planes. Commonly found in riverbeds, canyons, and coastal cliffs. Check for grain size and cement type.

Identified on: 4/18/2026

Mode: Standard