sedimentary

Jasper (Chocolate or Brown Jasper)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 on the Mohs scale. Color: Deep brown to reddish-brown. Luster: Vitreous to dull. Crystal Structure: Hexagonal (Microcrystalline). Cleavage: None (Conchoidal fracture). Specific Gravity: 2.58-2.91.

Hardness: 6
Color: Deep brown to reddish-brown
Luster: Vitreous to dull

Identified March 28, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the infiltration of silica-rich fluids into sedimentary or volcanic rock. Its deep brown color is caused by a high concentration of iron oxide (goethite or limonite) inclusions within the cryptocrystalline quartz structure.

Uses & applications

Primarily used for lapidary work including cabochons, beads, and ornamental carvings. It is also a popular collector's stone and used in metaphysical practices for its alleged 'grounding' properties.

Geological facts

Jasper has been used by ancient civilizations for thousands of years; the name 'Jasper' is derived from the Greek word 'iaspis', meaning spotted stone. Brown Jasper specifically has historically been used in seal making because it doesn't stick to hot wax.

Field identification & locations

Identify in the field by its waxy luster when broken, high hardness (cannot be scratched by a steel knife), and smooth, water-worn texture if found in riverbeds. Common locations include the Western USA (Oregon, Idaho), India, and Madagascar.

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