sedimentary
Sandstone (Greywacke/Siltstone variant)
Clastic Sedimentary Rock (composed primarily of Quartz SiO2 and Feldspar)
Hardness: 6-7 Mohs; Color: Tan, grey, or brownish-grey; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific gravity: 2.2–2.8
- Hardness
- 6-7 Mohs
- Color
- Tan, grey, or brownish-grey
- 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, grey, or brownish-grey; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific gravity: 2.2–2.8
Formation & geological history
Formed by the accumulation and lithification of mineral particles or rock fragments. These specimens are often rounded 'river stones' shaped by water erosion over hundreds to thousands of years, originating from much older deposits.
Uses & applications
Commonly used as a base material in construction, road fill, and sometimes as 'river rock' for landscaping and decorative garden paths.
Geological facts
Sandstone is one of the most common types of sedimentary rock and can preserve fossils. It is also an important aquifer, as its porosity allows it to hold significant amounts of water or oil underground.
Field identification & locations
Identify in the field by its gritty texture (feels like sandpaper) and rounded edges if found near water. Common globally in riverbeds and coastal areas. Collectors often use them for 'rock painting' hobbies.
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