sedimentary

Sandstone (specifically Arkose or Ferruginous Sandstone)

Sandstone (SiO2 with iron oxide inclusions)

AI-generated identification · may be incorrect

Hardness: 6-7 on Mohs scale (due to quartz content); Color: Reddish-brown, earthy; Luster: Dull or earthy; Crystal Structure: Clastic (granular); Cleavage: None; Specific Gravity: 2.2-2.8

Hardness: 6-7 on Mohs scale (due to quartz content)
Color: Reddish-brown, earthy
Luster: Dull or earthy

Identified May 7, 2026More sedimentary →

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Physical properties

Hardness: 6-7 on Mohs scale (due to quartz content); Color: Reddish-brown, earthy; Luster: Dull or earthy; Crystal Structure: Clastic (granular); 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 suggests iron-rich (ferruginous) cementation, often occurring in continental or arid environments like river beds or deserts over millions of years.

Uses & applications

Used widely in construction as a building stone and for paving. Higher-grade sandstones are used for glass manufacturing or as abrasive materials. Sometimes used in landscape gardening.

Geological facts

Sandstone makes up about 20-25% of all sedimentary rocks on Earth. The 'Old Red Sandstone' is a famous geological unit that contributed significantly to the early understanding of stratigraphy.

Field identification & locations

Identify in the field by its gritty texture (feels like sandpaper) and visible sand grains. It is commonly found in sedimentary basins and canyons. Collectors should look for distinct bedding planes or fossil inclusions.