sedimentary

Ferruginous Sandstone

Arenite with Iron-oxide cement

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale); Color: Brown, reddish-brown, tan with dark speckles; Luster: Dull/Earthy; Crystal structure: Clastic (sand grains); Cleavage: None; Specific gravity: 2.2 - 2.8.

Hardness: 6-7 (Mohs scale)
Color: Brown, reddish-brown, tan with dark speckles
Luster: Dull/Earthy

Identified April 10, 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 scale); Color: Brown, reddish-brown, tan with dark speckles; Luster: Dull/Earthy; Crystal structure: Clastic (sand grains); Cleavage: None; Specific gravity: 2.2 - 2.8.

Formation & geological history

Formed through the accumulation and cementation of sand-sized mineral particles (usually quartz) where iron oxides (like hematite or goethite) act as the binding agent. Typically forms in riverbeds, deserts, or shallow marine environments.

Uses & applications

Commonly used as a building stone, in road base construction, or for decorative landscaping due to its warm colors.

Geological facts

The reddish-brown color is a result of the oxidation of iron minerals, essentially making this rock a naturally 'rusted' piece of geological history.

Field identification & locations

Identify by its gritty, sandpaper-like texture and its characteristic dark-brown spotting (staining). Commonly found in sedimentary basins and eroded plateau regions.