Sandstone (Ferruginous)

Physical Properties

Hardness: 6-7 (Mohs); Color: Brown, reddish-brown, tan; Luster: Dull/Earthy; Crystal Structure: Clastic (sand grains); 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 brown color indicates the presence of iron oxide (hematite or limonite) acting as a cementing agent. Common in desert, river, and coastal environments.

Uses & Applications

Used primarily in construction as building stone, road base, and common landscaping. Highly ferruginous types can sometimes be used as low-grade iron ore.

Geological Facts

Sandstone accounts for about 20-25% of all sedimentary rocks on Earth. This specific specimen shows weathering patterns typical of river transport or wind erosion.

Field Identification & Locations

Identify by a gritty 'sandpaper' feel when rubbed. It can be found globally in outcrop formations. For collectors, look for unique weathering patterns or fossil inclusions.

Identified on: 4/20/2026

Mode: Standard