sedimentary
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (primarily SiO2 with Fe2O3)
Hardness: 6-7 (Mohs); Color: Reddish-brown to tan; Luster: Dull/Earthly; Crystal structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2–2.8
- Hardness
- 6-7 (Mohs)
- Color
- Reddish-brown to tan
- Luster
- Dull/Earthly
Identified More sedimentary →
Explore Sandstone (Ferruginous) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs); Color: Reddish-brown to tan; Luster: Dull/Earthly; Crystal structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2–2.8
Formation & geological history
Formed from the mechanical weathering of pre-existing rocks and the deposition of sand-sized grains in environments such as rivers, deserts, or beaches. The iron oxide (rust) acts as a cementing agent, giving it the characteristic brown color.
Uses & applications
Commonly used as a building material, in paving, for decorative landscaping, and as an aquifer in geology due to its porosity.
Geological facts
Sandstone makes up approximately 20-25% of all sedimentary rocks on Earth. The famous red rocks of the Grand Canyon and Petra in Jordan are primarily made of ferruginous sandstone.
Field identification & locations
Identify in the field by its gritty texture (feels like sandpaper) and visible sand grains. Look for layering (bedding). Found worldwide in sedimentary basins; collectors look for specimens with unique ripple marks or fossil inclusions.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
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 (primarily SiO2)
sedimentary