sedimentary
Sandstone (River Stone)
Arenite (primarily SiO2)
Hardness: 6-7 Mohs; Color: Tan, brown, or buff; Luster: Dull/Earthy; Crystal structure: Clastic (sand-sized grains); Cleavage: None; Specific gravity: 2.2-2.8
- Hardness
- 6-7 Mohs
- Color
- Tan, brown, or buff
- 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 Mohs; Color: Tan, brown, or buff; Luster: Dull/Earthy; Crystal structure: Clastic (sand-sized grains); Cleavage: None; Specific gravity: 2.2-2.8
Formation & geological history
Formed through the accumulation and cementation of sand-sized mineral particles or rock fragments, typically in riverbeds, deltas, or deserts. This specific specimen has been rounded by fluvial (river) erosion over thousands of years.
Uses & applications
Used primarily as decorative landscaping stone, in construction aggregates, and occasionally as a sharpening stone or for architectural veneers.
Geological facts
Sandstone accounts for about 10 to 20 percent of all sedimentary rocks on Earth. This rounded 'cobble' shape indicates it spent a significant amount of time being tumbled in a high-energy water environment like a river or beach.
Field identification & locations
Identify by its gritty, sandpaper-like texture and visible sand grains. Common in river basins and sedimentary outcrops worldwide. Collectors look for unique banding or fossil inclusions.
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