sedimentary

Black Jasper

Silicon Dioxide (SiO2) with Carbonaceous inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7.0 (Mohs scale), Color: Jet black with white/grey veins, Luster: Vitreous to waxy, Crystal Structure: Trigonal (Microcrystalline), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.58-2.91

Hardness: 6

Identified April 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the infiltration of silica in volcanic ash or fine-grained sediments. The black color is typically caused by organic matter or carbonaceous inclusions during the lithification process.

Uses & applications

Primarily used for lapidary work, jewelry (cabochons), talismans, and as polished decorative or meditation stones.

Geological facts

Black Jasper is sometimes specifically referred to as 'Basanite' or 'Lydian Stone' when used as a touchstone to test the purity of gold or silver. Unlike many other stones, jasper is opaque and does not transmit light even at the thin edges.

Field identification & locations

Identify by its extreme hardness (cannot be scratched by a steel knife), smooth conchoidal fracture, and absolute opacity. It is commonly found in India, Russia, Brazil, and the Southwestern USA.