Sandstone (Quartzose Sandstone)

Physical Properties

Hardness: 6-7 on Mohs scale (due to quartz content); Color: Tan, beige, off-white; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None (fractures across grains); Specific Gravity: 2.2 - 2.8.

Formation & Geological History

Formed from the accumulation and cementation of sand-sized mineral grains or rock fragments. This specimen appears water-worn, likely from a riverbed or coastal environment where mechanical weathering rounded its edges.

Uses & Applications

Commonly used as a construction material (building stone), as an abrasive in industrial processes, and as a reservoir rock for oil and natural gas in geological formations.

Geological Facts

Sandstone accounts for approximately 20% of all sedimentary rocks on Earth. Its porosity makes it an excellent natural filter for groundwater and a vital aquifer material.

Field Identification & Locations

Identify in the field by its sandpaper-like feel and visible grains. It is extremely common worldwide, especially in arid regions or ancient river systems. Use a hand lens to see individual sand grains held together by a mineral cement like silica or calcite.

Identified on: 4/14/2026

Mode: Standard