sedimentary
River Pebble (Chalcedony / Quartzite)
Silicon Dioxide (SiO2)
Mohs hardness of 6.5 to 7. Color is yellowish-brown to olive green with smooth, water-worn texture. Waxy to vitreous luster, microcrystalline to cryptocrystalline structure, no cleavage, specific gravity around 2.65.
Identified More sedimentary →
Explore River Pebble (Chalcedony / Quartzite) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness of 6.5 to 7. Color is yellowish-brown to olive green with smooth, water-worn texture. Waxy to vitreous luster, microcrystalline to cryptocrystalline structure, no cleavage, specific gravity around 2.65.
Formation & geological history
Formed by stream or river erosion over extended periods, rounding down larger silica-rich rocks, quartzites, or cherts into a smooth pebble.
Uses & applications
Commonly used in decorative landscaping, aquarium substrate, craft projects, or as river stone pocket stones.
Geological facts
Smooth river pebbles get their polished surface purely from mechanical abrasion against water, sand, and other stones over thousands of years.
Field identification & locations
Identify by its smooth rounded heart-like shape and waxy surface feel. Found along riverbeds, stream channels, and beaches worldwide.
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
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale
Argillaceous sedimentary rock
sedimentary
Mudstone
Argillite / Siliciclastic sedimentary rock
sedimentary