sedimentary
River Stone (River Rock)
Smooth Clastic Sedimentary Rock
AI-generated identification · may be incorrectMohs hardness of 6-7 (if silica-rich), variable colors of tan, grey, and yellow, dull to waxy luster, smooth well-rounded texture with small pits.
Identified More sedimentary →
Explore River Stone (River Rock) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness of 6-7 (if silica-rich), variable colors of tan, grey, and yellow, dull to waxy luster, smooth well-rounded texture with small pits.
Formation & geological history
Formed through long-term erosion and abrasion in riverbeds or coastal environments. The original parent rock could be igneous or sedimentary, further weathered over thousands of years.
Uses & applications
Commonly used in landscaping, decorative stone masonry, aquarium decor, and as massage stones.
Geological facts
The smooth surface is the result of 'saltation,' where rocks bounce along the bottom of a river, wearing away sharp edges through constant collision.
Field identification & locations
Identified by its rounded, water-worn shape and lack of sharp edges. Can be found in current or ancient riverbeds, beaches, and glacial deposits.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary