sedimentary

Red Sandstone

Arenite (Ferruginous Sandstone)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs); Color: Red, reddish-brown, or orange due to iron oxide (hematite); Luster: Dull/Earthy; Structure: Clastic; Cleavage: None; Specific Gravity: 2.2-2.8.

Hardness: 6-7 (Mohs)
Color: Red, reddish-brown, or orange due to iron oxide (hematite)
Luster: Dull/Earthy

Identified June 18, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs); Color: Red, reddish-brown, or orange due to iron oxide (hematite); Luster: Dull/Earthy; Structure: Clastic; Cleavage: None; Specific Gravity: 2.2-2.8.

Formation & geological history

Formed by the accumulation and cementation of sand-sized mineral grains or rock fragments. The red color indicates formation in an oxygen-rich environment (subaerial) where iron minerals oxidized. Often found in desert (aeolian) or river (fluvial) deposits ranging from Precambrian to Cenozoic eras.

Uses & applications

Widely used as a building material, paving stone, decorative garden rock, and in the manufacturing of glass and grindstones.

Geological facts

The red color is essentially 'rust' on the grains. Famous formations include the Grand Canyon, Petra in Jordan, and the Red Rocks of Sedona. It often contains fossils and records ripples from ancient water bodies.

Field identification & locations

Identify by its gritty texture (feels like sandpaper) and visible sand grains. Common in arid regions and coastal cliffs. Collectors look for unique banding or fossil inclusions. This specimen appears water-worn or shaped, suggesting a fluvial or coastal origin.