sedimentary

Jasper

Silicon Dioxide (Microcrystalline Quartz / Chalcedony)

Hardness of 6.5 to 7 on the Mohs scale, opaque luster, microcrystalline or cryptocrystalline crystal structure, conchoidal fracture with no true cleavage, and a specific gravity around 2.58 to 2.91. This specific specimen exhibits distinctive reddish-brown and orange tones, likely colored by iron oxide impurities.

Identified August 5, 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

Jasper forms through the silica-rich precipitation in marine or volcanic environments, often replacing organic material or filling cavities in rocks. Over millions of years, silica-laden fluids deposit microcrystalline quartz within sedimentary beds or hydrothermal veins.

Uses & applications

Commonly used for ornamental carvings, polished cabochons in jewelry, spheres, decorative sculptures, and favored as a collector's specimen.

Geological facts

Jasper has been used since antiquity for ancient seals, talismans, and weaponry tools. The vibrant red color is a result of iron oxide inclusions trapped during the mineral's formation process.

Field identification & locations

Easily identified by its opaque nature, waxy to dull luster, and inability to be scratched by a steel knife (hardness greater than 6). It is frequently found as water-worn pebbles along beaches, riverbeds, and within quartz-bearing geological formations worldwide.

Other sedimentary specimens

See all

Sandstone or Siltstone

Arenite (if sandstone)

Sedimentary

Fossiliferous Concretion

Septarian Concretion containing Brachiopods/Crinoids

fossil

Quartz pebble

Silicon dioxide (SiO2)

sedimentary

Generic Pebble / Rock Fragment

Lithic fragment / Weathered rock

sedimentary

Sedimentary Sandstone

Arenite (Sedimentary Rock)

sedimentary

Banded Siltstone / Mudstone Pebble

Siltstone / Argillite

sedimentary