sedimentary
Red Sandstone
Ferruginous Sandstone (SiO2 with Fe2O3)
Hardness: 6-7 (Mohs scale), Color: Reddish-brown/Terracotta, Luster: Dull/Earthy, Crystal Structure: Granular/Clastic, Cleavage: None, Specific Gravity: 2.2-2.8
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs scale), Color: Reddish-brown/Terracotta, Luster: Dull/Earthy, Crystal Structure: Granular/Clastic, Cleavage: None, Specific Gravity: 2.2-2.8
Formation & geological history
Formed through the accumulation and cementation of sand-sized grains, typically quartz and feldspar, in desert or river delta environments. The red color suggests deposition in an oxygen-rich environment where iron minerals oxidized into hematite.
Uses & applications
Commonly used as a building material, paving stone, decorative garden rock, and in the production of glass or concrete.
Geological facts
Red sandstone is famous for creating iconic landscapes like the Grand Canyon and the 'Red Rocks' of Sedona. It was one of the most popular building materials for prehistoric structures and 19th-century brownstone buildings.
Field identification & locations
Identify by its gritty sandpaper feel and visible sand grains. Found globally in basins and ancient desert regions. For collectors, look for ripple marks or cross-bedding indicating ancient water or wind flow.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary