Sandstone with Iron Oxide

Physical Properties

Hardness: 6-7 (Mohs scale), Color: tan, yellow, and brown, Luster: Dull/Earthy, Crystal Structure: Clastic granular, Cleavage: None, Specific Gravity: 2.2-2.8

Formation & Geological History

Formed by the accumulation and lithification of sand-sized mineral grains or rock fragments. The yellowish-brown tint is due to iron oxide (limonite or goethite) staining from groundwater interaction over millions of years.

Uses & Applications

Commonly used as a building stone, in paving, and as an abrasive. Finely ground sandstone is used in glass making and foundry molds.

Geological Facts

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

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and lack of distinct crystals or bubbles. Common in desert environments and river beds worldwide.

Identified on: 4/29/2026

Mode: Standard