Sandstone

Physical Properties

Hardness: 6-7 on Mohs scale; Color: Tan, brown, or earthy orange; Luster: Dull or earthy; Structure: Granular/clastic; Cleavage: None; Specific Gravity: 2.2-2.8

Formation & Geological History

Formed over millions of years by the accumulation and cementation of sand-sized mineral grains or rock fragments (usually quartz). Common in desert, river, and coastal environments.

Uses & Applications

Extensively used in construction for paving, building facades, and historically for grinding stones. Also acts as an important reservoir for groundwater and petroleum.

Geological Facts

Sandstone represents about 20-25% of all sedimentary rocks on Earth. The famous red rock formations in Sedona, Arizona, and the Grand Canyon are primarily types of sandstone.

Field Identification & Locations

Identify in the field by its gritty, sandpaper-like feel and visible grains. It is commonly found in dry, arid regions or ancient shorelines. Collectors should look for unique cross-bedding patterns.

Identified on: 5/2/2026

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