Sandstone

Physical Properties

Hardness: 6-7 on Mohs scale; Color: tan, yellow, or buff; Luster: dull/earthy; Crystal structure: granular/clastic; Cleavage: none; Specific gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation of sand-sized mineral particles or rock fragments. These are buried and cemented over millions of years by minerals like silica, calcite, or iron oxide, typically in river, desert, or marine environments.

Uses & Applications

Commonly used as a decorative building stone, in the manufacture of glass, as a reservoir for water or oil in the petroleum industry, and as flagstones for landscaping.

Geological Facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. The famous red rock formations of the American Southwest, such as those in the Grand Canyon and Zion National Park, are primarily composed of various layers of sandstone.

Field Identification & Locations

Identify in the field by its gritty, sand-like texture (feels like sandpaper). It often shows visible layering or cross-bedding. Look for it in areas with exposed sedimentary outcrop or ancient riverbeds.

Identified on: 4/14/2026

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