Sandstone

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Brown, tan, reddish-brown; Luster: Dull or earthy; Crystal Structure: Clastic (grainy); Cleavage: None; Specific Gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of mineral particles or rock fragments (clasts) usually primarily quartz or feldspar. They form over millions of years in deserts, riverbeds, and ocean floors.

Uses & Applications

Used widely in construction and masonry, paving stones, and as a reservoir rock for petroleum and natural gas due to its porosity.

Geological Facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. Some of the world's most famous natural arches and canyons, like the Grand Canyon, are primarily carved out of sandstone layers.

Field Identification & Locations

Identify in the field by its 'gritty' sandpaper feel when touched. It has visible grains and often shows distinct bedding or layering. Found globally in areas with ancient sedimentary basins.

Identified on: 5/17/2026

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