sedimentary
Sandstone (likely Siltstone or Mudstone variety)
Clastic Sedimentary Rock (primarily SiO2 with iron oxides)
Hardness: 6-7 on Mohs scale (if well-indurated); Color: Reddish-brown, terracotta, or tan; Luster: Dull/Earthy; Crystal structure: Non-crystalline (clastic texture); Cleavage: None (tends to fracture along bedding planes); Specific gravity: 2.2-2.8
- Hardness
- 6-7 on Mohs scale (if well-indurated)
- Color
- Reddish-brown, terracotta, or tan
- Luster
- Dull/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 (if well-indurated); Color: Reddish-brown, terracotta, or tan; Luster: Dull/Earthy; Crystal structure: Non-crystalline (clastic texture); Cleavage: None (tends to fracture along bedding planes); Specific gravity: 2.2-2.8
Formation & geological history
Formed by the accumulation of sand-sized or silt-sized grains often in arid, river, or lake environments. Red coloration indicates the presence of iron oxide (hematite) during lithification under oxidizing conditions. These specimens often date from the Permian or Triassic periods.
Uses & applications
Commonly used as building stone, pavers, and decorative landscaping. Fine-grained varieties are used in ceramics or as sharpeners. Small specimens are prized by collectors for their distinct layering.
Geological facts
The distinct bands visible in the specimen represent different periods of sediment deposition, also known as varves. Many famous landmarks, such as the Grand Canyon or Petra, are carved from similar red sandstone formations.
Field identification & locations
Identify in the field by its gritty texture (feels like sandpaper) and visible horizontal layering (bedding planes). When scratched with a steel nail, it often leaves a light-colored streak. Commonly found in desert regions or ancient riverbeds.
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