sedimentary

Ferruginous Sandstone

Arenite with Hematite/Goethite cement

AI-generated identification · may be incorrect

Hardness: 6-7 (approx); Color: Dark reddish-brown to maroon; Luster: Dull/Earthy; Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.5-3.0

Hardness: 6-7 (approx)
Color: Dark reddish-brown to maroon
Luster: Dull/Earthy

Identified June 13, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (approx); Color: Dark reddish-brown to maroon; Luster: Dull/Earthy; Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.5-3.0

Formation & geological history

Formation results from the deposition of sand-sized grains (mostly quartz) which are later cemented together by iron oxides (hematite or limonite) precipitated from groundwater. Commonly found in terrestrial or shallow marine environments.

Uses & applications

Used primarily as low-grade building stone, landscaping rock, or in some cases as a minor source of iron ore if the concentration is high enough.

Geological facts

The deep red color is caused by the oxidation of iron, essentially 'rust' within the rock. These rocks are often used to interpret past environmental conditions and water table history.

Field identification & locations

Identify by its gritty texture (sandpaper feel) and the characteristic reddish-brown streak it leaves on a porcelain plate. Common in regions with high iron content in the soil or ancient sea beds.