Sandstone (likely Ferruginous)

Physical Properties

Hardness: 6-7 (Mohs scale) if quartz-based. Color: Tan, brown, or reddish-brown due to iron oxidation. Luster: Dull/Earthy. Structure: Clastic, fine to medium-grained. Cleavage: None.

Formation & Geological History

Formed from the accumulation and cementation of sand-sized mineral particles or rock fragments. The reddish tint suggests it was formed in an oxygen-rich environment where iron-containing minerals oxidized.

Uses & Applications

Used in construction, as a decorative stone, or as an abrasive. In historical contexts, it is a primary material for architecture and sculpture.

Geological Facts

Sandstone accounts for about 20-25% of all sedimentary rocks. Famous structures like the treasury at Petra and the Red Fort in India are carved from or built with sandstone.

Field Identification & Locations

Identify by a 'sandpaper' feel; if you rub it, small grains may come loose. It often shows layering or bedding planes. Common in deserts, riverbeds, and coastal areas.

Identified on: 4/24/2026

Mode: Standard