Sandstone (Ferruginous)

Physical Properties

Hardness: 6-7 (individual grains); Color: tan, yellow-brown, and reddish due to iron oxides; Luster: dull to earthy; Structure: granular, clastic texture; 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. Usually deposited in riverbeds, deserts, or marine environments. This specimen shows significant iron oxide staining (limonite/hematite).

Uses & Applications

Used primarily in building construction as a dimension stone, road base material, and as an abrasive in some industrial processes.

Geological Facts

Sandstone makes up about 20-25% of the sedimentary rocks on Earth. The distinct coloring in this piece suggests it has been exposed to oxygen and water, causing the iron minerals to 'rust' or oxidize.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and the presence of visible grains. Common in canyon regions and sedimentary basins worldwide.

Identified on: 5/19/2026

Mode: Standard