sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs); Color: Tan, brownish-red, or gray; Luster: Dull/Earthy; Crystal structure: Clastic (granular texture); Cleavage: None; Specific Gravity: 2.2 - 2.8

Hardness: 6-7 (Mohs)
Color: Tan, brownish-red, or gray
Luster: Dull/Earthy

Identified April 3, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs); Color: Tan, brownish-red, or gray; Luster: Dull/Earthy; Crystal structure: Clastic (granular texture); Cleavage: None; Specific Gravity: 2.2 - 2.8

Formation & geological history

Formed through the accumulation and cementation of mineral particles or rock fragments (sand-sized). The reddish hue in this specimen suggests iron-oxide (hematite) staining, typically formed in terrestrial or shallow marine environments.

Uses & applications

Used widely in construction (building stone/tiles), as a source of silica for glass making, and as a reservoir rock in the petroleum industry.

Geological facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. Its porosity and permeability make it an excellent natural aquifer for storing groundwater.

Field identification & locations

Identify in the field by its 'sandpaper' feel when rubbed. It can be found in deserts, riverbeds, and coastal regions globally. Collectors look for unique banding or fossil inclusions.