Sandstone

Physical Properties

Hardness: 6-7 Mohs; Color: Tan, grey, or light green/yellow; Luster: Dull/Earthy; Crystal Structure: Clastic (grainy texture); Cleavage: None; Specific Gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of mineral grains or rock fragments (sands) over millions of years, typically in desert, river, or ocean environments.

Uses & Applications

Extensively used in construction for tiles, paving, and monuments. Also used as a reservoir rock in the petroleum industry and for glass making if high in quartz.

Geological Facts

Sandstone accounts for roughly 20 to 25 percent of all sedimentary rocks in the Earth's crust. It is a major aquifer for groundwater storage.

Field Identification & Locations

Identify by its 'sandpaper' feel and visible grains. Often found in layered outcrops or as rounded pebbles in riverbeds. Collectors look for unique banding or fossil inclusions.

Identified on: 4/26/2026

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