Sandstone

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Tan, yellow, brown; Luster: Dull or earthy; Crystal structure: Clastic/Granular; Cleavage: None; Specific gravity: 2.2-2.8

Formation & Geological History

Formed from the accumulation of sand-sized grains, typically quartz or feldspar, deposited in environments like deserts, river beds, or beaches. Over millions of years, pressure and mineral cements (like silica or calcium carbonate) bind the grains into rock.

Uses & Applications

Widely used in construction for building stone, paving, and decorative facades. It is also used as a reservoir rock for oil and natural gas and as a source of high-purity silica for glassmaking.

Geological Facts

Sandstone can preserve fossilized footprints and ripple marks from ancient water bodies. It is the primary component of famous geological landmarks like the Grand Canyon and Petra.

Field Identification & Locations

Identified by its gritty, sandpaper-like feel and visible grains. Often occurs in distinct layers or beds in cliffs and outcrops worldwide. Collect specimens that show unique colors or cross-bedding.

Identified on: 4/29/2026

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