Sandstone

Physical Properties

Mohs hardness of 6-7 (individual grains), color ranges from tan, brown, yellow, to grey. Luster is dull/earthy. It has a clastic texture with sandpaper-like feel. Crystal structure is granular. Specific gravity is 2.2-2.8.

Formation & Geological History

Formed by the accumulation, compaction, and lithification of sand-sized mineral particles or rock fragments. Often formed in desert, river, or coastal environments over millions of years (commonly Phanerozoic eon).

Uses & Applications

Widely used as an architectural building stone, flagstone for walkways, grindstones for sharpening, and as a reservoir rock for oil, gas, and groundwater.

Geological Facts

Sandstone is one of the most common types of sedimentary rock and often contains fossils. It serves as a vital natural filter for groundwater aquifers due to its porosity.

Field Identification & Locations

Identify by its gritty texture (feels like sandpaper) and distinct layering (bedding). Rubbing two pieces together will usually release sand grains. Found globally in areas with ancient sedimentary basins.

Identified on: 5/8/2026

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