sedimentary

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale), Color: Brownish-red to tan (due to iron oxide), Luster: Dull/Earthy, Crystal Structure: Granular/Clastic, Cleavage: None, Specific Gravity: 2.0-2.6

Identified April 2, 2026More sedimentary →

Explore Sandstone (Ferruginous) 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 scale), Color: Brownish-red to tan (due to iron oxide), Luster: Dull/Earthy, Crystal Structure: Granular/Clastic, Cleavage: None, Specific Gravity: 2.0-2.6

Formation & geological history

Formed from the accumulation and cementation of sand-sized mineral grains or rock fragments. The reddish-brown tint suggests oxidation (rusting) of iron minerals within the pore spaces over geological time, typically in terrestrial or shallow marine environments.

Uses & applications

Common sandstone is used in construction as building stone, pavers, and as a source of silica for glass manufacturing. Smaller specimens are primarily used for educational or basic collection purposes.

Geological facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. The famous red rocks of the Grand Canyon and Zion National Park are composed largely of this type of iron-stained sandstone.

Field identification & locations

Identify in the field by its gritty, sandpaper-like feel. It can often be scratched by a steel blade, but the individual quartz grains themselves are very hard. Look for visible layers (bedding) or cross-bedding in larger outcrops.