sedimentary

Jasper

Microcrystalline Quartz (SiO2)

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

Hardness: 6

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 from the precipitation of silica-rich fluids in sedimentary environments, or as a primary filling in volcanic rocks and hydrothermal veins. Often associated with ancient marine deposits and can range in geological age from Precambrian to recent.

Uses & applications

Used widely in ornamental carvings, cabochons for jewelry, decorative objects, and as a popular specimen for lapidary work and rock tumbling.

Geological facts

Jasper has been used by ancient civilizations for thousands of years to create tools, seals, and ornate jewelry. Its name comes from the ancient Greek word iaspis, meaning 'spotted stone'.

Field identification & locations

Can be identified in the field by its smooth, water-worn appearance in riverbeds, waxy or dull luster, lack of cleavage, and high hardness which scratches glass. Found worldwide, particularly in river gravels, volcanic regions, and areas with ancient sedimentary deposits.