sedimentary

Yellow Jasper

Jasper (Silicon Dioxide, SiO2)

Hardness: 6.5–7 on the Mohs scale. Color: Opaque yellow to mustard golden with occasional mottling. Luster: Vitreous to waxy. Crystal Structure: Trigonal (microcrystalline). Cleavage: None (conchoidal fracture). Specific Gravity: 2.6–2.9.

Hardness: 6
Color: Opaque yellow to mustard golden with occasional mottling
Luster: Vitreous to waxy

Identified March 28, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the precipitation of silica from volcanic fluids or in sedimentary environments where silica-rich groundwater replaces organic matter or mineral grains. The yellow color typically comes from iron oxide (goethite) inclusions.

Uses & applications

Predominantly used for jewelry (pendants, cabochons), ornamental carvings, and 'metaphysical' healing stones. Historically used for making tools due to its hardness and sharp fracture edges.

Geological facts

Jasper has been used by ancient civilizations for millennia; yellow jasper specifically was often used in Egyptian and Native American talismans for protection and travel. Because it is microcrystalline, it avoids the transparency of standard quartz.

Field identification & locations

Identify in the field by its opacity (unlike citrine which is transparent), high hardness (cannot be scratched by a steel knife), and smooth conchoidal fracture. Common locations include India, South Africa, Australia, and the western United States.