Sandstone

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Tan, beige, grey, or reddish-brown; Luster: Dull or earthy; Crystal structure: Granular/clastic; 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. This specimen appears to be an outcrop or weathered block found in temperate grassland environments, likely formed over millions of years by river deposits or aeolian transport.

Uses & Applications

Used extensively in construction as building stone, pavers, and crushed aggregate. Fine-grained variants are used for grindstones.

Geological Facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. It is a major reservoir for groundwater and petroleum because of its high porosity and permeability.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and visible layers or bedding. Use a magnifying glass to see individual grains of quartz or feldspar. It is common worldwide in canyons, cliffs, and quarries.

Identified on: 4/20/2026

Mode: Standard