Sandstone

Physical Properties

Hardness: 6-7 (individual grains); Color: Tan, brown, or buff; Luster: Dull or earthy; Crystal structure: Clastic/granular; Cleavage: None; Specific Gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments. Typically deposited in river, lake, or marine environments over millions of years.

Uses & Applications

Used widely as a building material, masonry decoration, road gravel, and as a source of high-purity silica for glass manufacturing.

Geological Facts

Sandstone reservoirs are one of the most important sources of ground water and petroleum because of their high porosity and permeability.

Field Identification & Locations

Identify by a 'gritty' sandpaper feel when rubbed. Found worldwide in sedimentary basins. Collectors often look for specimens with interesting 'Liesegang rings' or fossil inclusions.

Identified on: 4/13/2026

Mode: Standard