Sandstone

Physical Properties

Hardness: 6-7 (Mohs scale) depending on cementation; Color: Tan, beige, or white with reddish oxidization; Luster: Dull/Earthy; Crystal structure: Clastic (granular); Cleavage: None; Specific gravity: 2.2-2.8

Formation & Geological History

Formed from the accumulation and lithification of sand-sized mineral grains or rock fragments. Typically deposited in desert, river, or coastal environments over millions of years through compaction and cementation by minerals like silica or calcite.

Uses & Applications

Commonly used in construction as a building stone, paving material, and in the production of glass (if high silica content). Historically significant for monumental architecture.

Geological Facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. The famous 'Red Rocks' in Colorado and the Treasury at Petra are both carved or formed from varieties of sandstone.

Field Identification & Locations

Identify in the field by its 'sandpaper' feel and visible grains. It can be found globally in outcrop formations and sedimentary basins. Test by rubbing: if individual sand grains dislodge, it is likely sandstone.

Identified on: 4/25/2026

Mode: Standard