sedimentary

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs); Color: Reddish-brown, tan, or gray; Luster: Dull/Earthy; Crystal Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8

Hardness: 6-7 (Mohs)
Color: Reddish-brown, tan, or gray
Luster: Dull/Earthy

Identified June 28, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs); Color: Reddish-brown, tan, or gray; Luster: Dull/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, typically in desert, river, or coastal environments. This specimen shows significant weathering and iron oxidation (rusting), common in Paleozoic to Mesozoic formations.

Uses & applications

Used widely in construction as building stone, pavers, and crushed aggregate. Fine-grained pure varieties are used for glassmaking or as sharpening stones.

Geological facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. The red color in many famous geological formations, like those in the Grand Canyon or Sedona, is caused by tiny amounts of iron oxide coating the sand grains.

Field identification & locations

Identify in the field by its gritty 'sandpaper' texture and visible layers (bedding planes). When scratched with steel, it usually leaves a mark due to the quartz hardness. Commonly found in riverbeds and outcrop cliffs.