sedimentary

Jasper

Silicon dioxide (Microcrystalline quartz, SiO2)

Hardness: 6.5 to 7 on the Mohs scale. Color: Brown, red, yellow, green, or multicolored. Luster: Vitreous to dull. Crystal structure: Trigonal (microcrystalline/cryptocrystalline). Cleavage: None, exhibits conchoidal fracture. Specific gravity: 2.58 to 2.91.

Hardness: 6
Color: Brown, red, yellow, green, or multicolored
Luster: Vitreous to dull

Identified August 3, 2026More sedimentary →

Explore Jasper 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 via the precipitation of silica-rich fluids or silicious oozes in marine or hydrothermal environments, often later undergoing diagenesis and weathering.

Uses & applications

Used for ornamental carvings, polished stones, cabochons in jewelry, and occasionally as an abrasive or decorative aggregate.

Geological facts

Jasper has been utilized by humans since ancient times for tools, seals, and ornamental items. Its name comes from the Old French 'jaspre' and Latin 'iaspidem', meaning 'spotted or speckled stone'.

Field identification & locations

Found worldwide in sedimentary and volcanic deposits, often as pebbles in riverbeds due to its high resistance to weathering. Identify by its waxy luster, conchoidal fracture, and inability to be scratched by a steel knife.

Other sedimentary specimens

See all

Sandstone or Siltstone

Arenite (if sandstone)

Sedimentary

Quartz pebble

Silicon dioxide (SiO2)

sedimentary

Fossiliferous Concretion

Septarian Concretion containing Brachiopods/Crinoids

fossil

Generic Pebble / Rock Fragment

Lithic fragment / Weathered rock

sedimentary

Sedimentary Sandstone

Arenite (Sedimentary Rock)

sedimentary

Banded Siltstone / Mudstone Pebble

Siltstone / Argillite

sedimentary