sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Iron Oxide staining)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs scale); Color: Brown, reddish-tan, earthy; Luster: Dull or earthy; Crystal structure: Granular (clastic); Cleavage: None; Specific gravity: 2.2-2.8

Hardness: 6-7 (Mohs scale)
Color: Brown, reddish-tan, earthy
Luster: Dull or earthy

Identified April 12, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs scale); Color: Brown, reddish-tan, earthy; Luster: Dull or earthy; Crystal structure: Granular (clastic); Cleavage: None; Specific gravity: 2.2-2.8

Formation & geological history

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments. The reddish-brown color indicates the presence of iron oxide (hematite or limonite) as a cementing agent or coating. Found in deserts, river beds, and ancient ocean floors.

Uses & applications

Used primarily in construction as a building stone or road base, as decorative landscaping rock, and occasionally in glass manufacturing if pure quartz sand is present.

Geological facts

Sandstone can preserve fossilized footprints and trackways better than many other rock types. It represents about 10-25% of all sedimentary rocks on Earth.

Field identification & locations

Identify by its gritty, abrasive texture (like sandpaper) and visible grains. Often found in layered outcrops. Collectors look for unique banding or fossil inclusions.