sedimentary
River Rock (Sandstone or Quartzite)
Clastic Sedimentary Rock / Quartzite
Hardness: 6-7 (Mohs scale), Color: earthy tan to gray, Luster: dull/matte (pearly when wet), Crystal structure: granular, Cleavage: none, Specific gravity: 2.6-2.7
Identified More sedimentary →
Explore River Rock (Sandstone or Quartzite) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs scale), Color: earthy tan to gray, Luster: dull/matte (pearly when wet), Crystal structure: granular, Cleavage: none, Specific gravity: 2.6-2.7
Formation & geological history
Formed through the accumulation of sand grains (quartz) under pressure in marine or desert environments, followed by rounding via water erosion in a riverbed or shoreline.
Uses & applications
Commonly used in landscaping, decorative ground cover, construction aggregate, and as a natural material for stone painting or meditation (worry stones).
Geological facts
The rounded shape indicates a high degree of maturity, meaning the rock has traveled a long distance from its original source, being tumbled and smoothed by water over thousands of years.
Field identification & locations
Identify by its smooth, rounded edges and granular texture. Found globally in active or ancient riverbeds, beaches, and glacial deposits. Low rarity but high utility for landscaping.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Banded Siltstone / Mudstone Pebble
Siltstone / Argillite
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary