sedimentary

Sandstone (Ferruginous)

Arenite (with Iron Oxide)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale); Color: Brown, reddish-tan, and earthy ochre; Luster: Dull/Earthy; Crystal Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.1 - 2.8

Hardness: 6-7 (Mohs scale)
Color: Brown, reddish-tan, and earthy ochre
Luster: Dull/Earthy

Identified April 12, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale); Color: Brown, reddish-tan, and earthy ochre; Luster: Dull/Earthy; Crystal Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.1 - 2.8

Formation & geological history

Formed through the accumulation and cementation of sand-sized silicate grains. The reddish-brown tint indicates the presence of iron oxide (hematite or limonite) as a cementing agent or staining. These rocks can form in deserts, riverbeds, or coastal environments over millions of years.

Uses & applications

Commonly used as a building material, road base, or aggregate. In some cases, it is used for grindstones or decorative landscaping rocks.

Geological facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. The famous 'Red Rocks' of the American West are examples of ferruginous sandstone where iron oxidation has occurred.

Field identification & locations

Identify in the field by its gritty, sandpaper-like texture and visible grains. Often displays bedding layers. It is ubiquitous in sedimentary basins worldwide.