sedimentary

Sandstone (Red Sandstone / River Stone)

Arenite (composed primarily of Quartz, SiO2, with Iron Oxide cementation)

AI-generated identification · may be incorrect

Hardness: 6-7 Mohs; Color: Reddish-brown to tan; Luster: Dull/Earthy; Structure: Clastic, fine-grained; Texture: Gritty like sandpaper; Cleavage: None.

Hardness: 6-7 Mohs
Color: Reddish-brown to tan
Luster: Dull/Earthy

Identified April 12, 2026More sedimentary →

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Physical properties

Hardness: 6-7 Mohs; Color: Reddish-brown to tan; Luster: Dull/Earthy; Structure: Clastic, fine-grained; Texture: Gritty like sandpaper; Cleavage: None.

Formation & geological history

Formed through the accumulation and compaction of mineral grains or rock fragments. The red color suggests deposition in an oxygen-rich environment (arid or fluvial) where iron minerals oxidized. This specific specimen has been rounded by fluvial (river) or marine (beach) erosion.

Uses & applications

Construction (flagstone, pavers), glass manufacturing (if high silica), architectural masonry, and household decor/garden stones.

Geological facts

Red sandstone is famous for creating the landscape of the American Southwest, such as the Grand Canyon and Antelope Canyon. It is also the primary material used for many historical 'brownstone' buildings in New York.

Field identification & locations

Identify in the field by its gritty texture and visible sand grains. It is extremely common in sedimentary basins, riverbeds, and coastal areas. It is often found in stratified layers called bedding.