Sandstone with Iron Oxide (Limonite/Hematite)

Physical Properties

Hardness: 6-7 (approximate due to quartz content); Color: Rusty brown, reddish-orange, tan; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.3-2.6

Formation & Geological History

Formed through the accumulation of sand-sized mineral particles or rock fragments, minerals are cemented together by silica or iron oxides during lithification. The iron staining occurs through oxidation in terrestrial environments.

Uses & Applications

Used primarily as building stone, pavers, and decorative landscaping. In some regions, highly ferruginous versions have historically been used as a low-grade iron ore.

Geological Facts

Sandstone makes up about 20-25% of all sedimentary rocks. The red and orange hues are often called 'desert varnish' when found in arid environments.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and visible layering or bedding planes. It is commonly found in river beds, deserts, and coastal areas.

Identified on: 4/27/2026

Mode: Standard