Sandstone

Physical Properties

Hardness: 6-7 (Mohs); Color: Grey, tan, white with reddish iron staining; Luster: Dull/Earthy; Crystal structure: Clastic (granular); Cleavage: None; Specific gravity: 2.2–2.8

Formation & Geological History

Formed from the accumulation and cementation of mineral particles or rock fragments (silica/quartz) over millions of years, typically in desert, river, or ocean environments.

Uses & Applications

Used widely in construction for building stone, paving, and as an aggregate. High-purity silica sandstone is used in glass manufacturing.

Geological Facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. Familiar landmarks like the Grand Canyon or the 'Red Rocks' of the American West are composed largely of various sandstone layers.

Field Identification & Locations

Identify by its gritty, sandpaper-like texture and visible grains. Often displays bedding planes or layering. Look for it in areas with historical water activity or exposed cliffs.

Identified on: 4/20/2026

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