sedimentary

Jasper

Microcrystalline Quartz (SiO2)

Hardness of 6.5 to 7 on the Mohs scale, typically opaque with a waxy to dull luster. It displays a conchoidal fracture and comes in a wide variety of colors due to mineral impurities, including red, yellow, brown, and green, often with banded or patterned appearances. Specific gravity ranges from 2.55 to 2.91.

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

Forms primarily from the precipitation of silica-rich fluids in sedimentary environments or hydrothermal veins, often replacing existing carbonate rocks or volcanic ash over millions of years.

Uses & applications

Used extensively for ornamental carvings, polished cabochons in jewelry, decorative objects, and as a popular specimen for rock collectors.

Geological facts

Jasper has been used by ancient civilizations since prehistoric times for making tools, weapons, seals, and fine jewelry. The name comes from the ancient Greek word iaspis, meaning spotted or speckled stone.

Field identification & locations

Can be identified in the field by its high hardness (scratches glass), lack of visible crystal structure (microcrystalline), waxy luster, and opaque earthy or multicolored appearance. Found worldwide in riverbeds, mountainous regions, and ancient sedimentary deposits.