sedimentary

Red Sandstone

Arenite (Ferruginous Sandstone)

Hardness: 6-7 (Mohs); Color: Reddish-brown due to iron oxide (hematite); Luster: Dull/Earthy; Crystal structure: Clastic texture with sand-sized grains; Cleavage: None; Specific gravity: 2.2-2.8.

Hardness: 6-7 (Mohs)
Color: Reddish-brown due to iron oxide (hematite)
Luster: Dull/Earthy

Identified June 28, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs); Color: Reddish-brown due to iron oxide (hematite); Luster: Dull/Earthy; Crystal structure: Clastic texture with sand-sized grains; Cleavage: None; Specific gravity: 2.2-2.8.

Formation & geological history

Formed by the accumulation of sand-sized mineral particles or rock fragments, cemented together by silica or iron oxide. This specimen shows water-worn rounding, likely from a fluvial (river) or coastal environment. Common in geological periods like the Permian or Triassic.

Uses & applications

Used widely as a building material, decorative stone in landscaping, and in the production of glass (if silica content is high).

Geological facts

The vibrant red color comes from the oxidation of iron minerals, essentially making it 'rusted' rock. The iconic formations of the Grand Canyon and Zion National Park are composed largely of various sandstone layers.

Field identification & locations

Identify in the field by its gritty 'sandpaper' feel and visible grains. It is commonly found in desert basins, riverbeds, and beach deposits across the American Southwest and Northern Europe.