sedimentary

Jasper pebble

Silicon Dioxide (SiO2 with iron oxide inclusions)

Hardness of 6.5 to 7 on the Mohs scale, earthy to sub-vitreous or waxy luster, opaque, sub-conchoidal fracture, microcrystalline quartz aggregate structure. Displays a dual-tone reddish-brown and dark charcoal hue.

Identified July 26, 2026More sedimentary →

Explore Jasper pebble in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through the deposition of silica from water solutions into cracks, cavities, or volcanic ash layers, enriched with hematite and other iron minerals which impart the deep red and dark colors. Typically water-worn and rounded in riverbeds or coastal environments.

Uses & applications

Used widely for lapidary arts, tumbling, jewelry making (cabochons and beads), decorative stone carvings, and personal rock collections.

Geological facts

Jasper is an opaque variety of chalcedony that gets its distinctive red, brown, and yellow colors from iron oxide inclusions. Rounded smooth river-pebble forms like this are popular among rockhounds and tumblers.

Field identification & locations

Identified by its high hardness (cannot be scratched by a steel nail), smooth water-rounded surface, completely opaque body, and rich reddish-brown coloration. Commonly found in gravel bars, riverbeds, beaches, and glaciated regions near iron-bearing volcanic or sedimentary deposits.

Other sedimentary specimens

See all

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

Sedimentary Shale

sedimentary

Shale and Pebble Fragment

Sedimentary Rock (Mudstone/Shale with Silica Pebble)

sedimentary