Sandstone

Physical Properties

Hardness: 6-7 (Mohs scale), Color: tan, grey, or light brown, Luster: dull/earthy, Crystal structure: granular/clastic, Grain size: 0.0625 to 2 mm diameter, Cleavage: none (fractures across grains)

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments, typically in environments like deserts, river deltas, or beaches. Geological ages vary from Precambrian to Cenozoic.

Uses & Applications

Extensively used in construction for flagstones, pavers, and building facades. Also used in the glass industry as a source of high-purity silica and as a reservoir rock for oil and gas.

Geological Facts

Sandstone makes up about 10-20% of the Earth's total sedimentary rock record. It is porous and often acts as a natural aquifer for groundwater.

Field Identification & Locations

Identify by its 'sandpaper' feel and visible layers (bedding) or grain structure. It often leaves a sandy residue when rubbed. Common in arid climates and coastal regions.

Identified on: 4/25/2026

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