sedimentary
Red Sandstone
Arenite (with Iron Oxide / Hematite staining)
Hardness: 6-7 on Mohs scale (due to quartz content); Color: Pink to deep reddish-brown; Luster: Dull to earthy; Crystal Structure: Clastic (granular); Cleavage: None (breaks across grains); Specific Gravity: 2.2 - 2.8.
- Hardness
- 6-7 on Mohs scale (due to quartz content)
- Color
- Pink to deep reddish-brown
- Luster
- Dull to earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 on Mohs scale (due to quartz content); Color: Pink to deep reddish-brown; Luster: Dull to earthy; Crystal Structure: Clastic (granular); Cleavage: None (breaks across grains); Specific Gravity: 2.2 - 2.8.
Formation & geological history
Formed through the accumulation and cementation of sand-sized mineral grains (primarily quartz). The reddish hue is caused by the oxidation of iron minerals (hematite) within the cementing matrix. Often formed in arid terrestrial environments like deserts or river floodplains.
Uses & applications
Extensively used in construction as a building stone (brownstone), flagstone for landscaping, and crushed stone for road base. In the lapidary arts, it is occasionally used for decorative carvings.
Geological facts
Famous structures made of red sandstone include the 'Red Fort' in Delhi and many of the iconic 'Brownstone' buildings in New York City. The staining acts as a record of historical oxygen levels in the atmosphere during deposition.
Field identification & locations
Identify by its gritty, sandpaper-like feel and visible grains. It can be found globally, with massive deposits in the Southwestern United States (Grand Canyon, Sedona) and Scotland. Collectors should look for cross-bedding patterns or ripple marks within the layers.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary