sedimentary

Jasper

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Olive green to brownish-green; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific gravity: 2.58-2.91

Hardness: 6
Color: Olive green to brownish-green
Luster: Vitreous to waxy

Identified March 23, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Olive green to brownish-green; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific gravity: 2.58-2.91

Formation & geological history

Formed through the deposition of silica from water or within volcanic ash layers that become consolidated under pressure and heat. It is a microcrystalline variety of quartz containing impurities of iron oxides and hydroxides.

Uses & applications

Commonly used in jewelry as cabochons, for ornamental carvings, and widely collected by rockhounds and hobbyists.

Geological facts

Jasper has been used throughout history as a gemstone. In ancient times, green jasper was often used for seals and amulets. The name comes from the Greek word 'iaspis', meaning 'spotted stone.'

Field identification & locations

Identify in the field by its smooth, waxy texture when polished and its conchoidal (shell-like) fracture pattern. It cannot be scratched by a steel knife. Common in riverbeds and areas with significant volcanic history.