Sandstone (Quartz Arenite)

Physical Properties

Hardness: 6-7 (Mohs scale), Color: Brownish-red to tan, Luster: Dull/Earthy, Crystal Structure: Granular/Clastic, Cleavage: None (fractures across grains), Specific Gravity: 2.2-2.8

Formation & Geological History

Formed from the accumulation and cementation of sand-sized mineral grains or rock fragments. Formed in high-energy environments like beaches, deserts, or riverbeds through lithification. Age varies by location, often millions of years old.

Uses & Applications

Construction (building stone, flagstone), aquifers (groundwater storage), industrial sand for glass-making, and decorative architectural elements.

Geological Facts

Sandstone is one of the most common sedimentary rocks. The famous 'Red Rocks' of the American Southwest are iconic examples of massive sandstone formations, colored by iron oxide (rust).

Field Identification & Locations

Identify in the field by its gritty 'sandpaper' texture. It can be found globally in outcrops and riverbeds. Look for bedding layers or cross-lamination indicating ancient flow patterns.

Identified on: 4/26/2026

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