sedimentary
River Pebble (Grey Quartzite / Sandstone Gravel)
Quartz-rich Sedimentary / Metamorphic River Pebble
AI-generated identification · may be incorrectHardness: 6-7 on Mohs scale; Color: Light grey to dull bluish-grey with subtle earthy weathering stains; Luster: Dull to sub-vitreous; Texture: Fine-grained, smooth, water-worn, and rounded by fluvial erosion; Specific Gravity: Approx. 2.65.
- Hardness
- 6-7 on Mohs scale
- Luster
- Dull to sub-vitreous
Identified More sedimentary →
Explore River Pebble (Grey Quartzite / Sandstone Gravel) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 on Mohs scale; Color: Light grey to dull bluish-grey with subtle earthy weathering stains; Luster: Dull to sub-vitreous; Texture: Fine-grained, smooth, water-worn, and rounded by fluvial erosion; Specific Gravity: Approx. 2.65.
Formation & geological history
Formed through fluvial (river/stream) transport and natural abrasion of silica-rich rocks like sandstone or meta-quartzite over thousands of years.
Uses & applications
Commonly used in landscaping, riverbed garden decoration, aquarium substrates, concrete aggregate, and casual rock painting.
Geological facts
Water-worn pebbles get their smooth, rounded shapes from continuous tumbling against other rocks in flowing river currents or ocean waves over long periods.
Field identification & locations
Found along riverbanks, lakeshores, beach coastlines, and glacial gravel deposits worldwide. Identified by its rounded, smooth surface and hard, silica-dominated composition.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary