Igneous or Sedimentary (water-worn)
River Rock (likely Basalt or Greywacke)
Basalt or Lithic Sandstone
AI-generated identification · may be incorrectHardness: 5-7, Color: Gray/dark gray, Luster: Dull to slightly waxy in spots, Structure: Fine-grained, rounded by water action.
Identified More igneous or sedimentary (water-worn) →
Explore River Rock (likely Basalt or Greywacke) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5-7, Color: Gray/dark gray, Luster: Dull to slightly waxy in spots, Structure: Fine-grained, rounded by water action.
Formation & geological history
Formed either from rapidly cooling lava (basalt) or sedimentary processes (greywacke), subsequently weathered and rounded by fluvial (river) or coastal action.
Uses & applications
Commonly used in landscaping, construction aggregate, and hardscaping.
Geological facts
River rocks are not a specific geological type but rather any rock that has been smoothed and rounded by the action of moving water.
Field identification & locations
Identified by its smooth, rounded shape and lack of sharp edges, typically found in riverbeds and on beaches.
More like this
Other igneous or sedimentary (water-worn) specimens
Quartz pebble (Agate / Chalcedony)
Silicon Dioxide (SiO2)
mineral
Quartz (Pebble)
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Tumbled Agate
Silicon Dioxide (Chalcedony / Quartz)
gemstone