Sandstone
Arenite (composed primarily of SiO2)
Rock Type: sedimentary

Physical Properties
Hardness: 6-7 (on Mohs scale if quartz-rich); Color: Tan, brown, or grayish; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8
Formation & Geological History
Formed through the accumulation and cementation of mineral particles or rock fragments (sand) over millions of years in environments like beaches, deserts, or river deltas.
Uses & Applications
Commonly used as a building material, in road construction, for making grindstones, and as a reservoir rock for oil and natural gas.
Geological Facts
Sandstone accounts for roughly 20% of all sedimentary rocks on Earth. The famous red rocks of the Grand Canyon and Petra in Jordan are primarily made of sandstone.
Field Identification & Locations
Identify in the field by its distinctive 'sandpaper' feel and visible grains. It is extremely common worldwide and often found in bedded layers or outcropping cliffs.
Identified on: 4/27/2026
Mode: Standard