sedimentary

Ferruginous Sandstone

Arenite with Iron-Oxide Cement

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs). Color: Tan, brown, or dark red/orange due to iron oxidation. Luster: Dull to earthy. Structure: Granular/clastic. Cleavage: None.

Hardness: 6-7 (Mohs)
Color: Tan, brown, or dark red/orange due to iron oxidation
Luster: Dull to earthy

Identified June 21, 2026More sedimentary →

Explore Ferruginous Sandstone 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). Color: Tan, brown, or dark red/orange due to iron oxidation. Luster: Dull to earthy. Structure: Granular/clastic. Cleavage: None.

Formation & geological history

Formed through the lithification of sand grains where iron minerals (like hematite or goethite) act as the binding cement. Commonly found in terrestrial or shallow marine environments with fluctuating water tables.

Uses & applications

Used primarily as low-grade building stone, road fill, and sometimes as a minor source of iron ore if the concentration is high enough.

Geological facts

This rock's distinct reddish-orange staining is essentially 'rock rust'. In many arid regions, it forms a resistant layer known as a 'duricrust' that protects the ground from erosion.

Field identification & locations

Identify by its gritty, sand-paper like feel and the presence of reddish-orange oxidation patches on a tan or grey matrix. Commonly found in desert mesas or riverbeds.