sedimentary

Black Jasper

Silicon Dioxide (SiO2) with carbon/iron impurities

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs); Color: Black with grey or white veining; Luster: Vitreous to dull; Crystal structure: Trigonal (Microcrystalline); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Black with grey or white veining
Luster: Vitreous to dull

Identified July 20, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Black with grey or white veining; Luster: Vitreous to dull; Crystal structure: Trigonal (Microcrystalline); Specific Gravity: 2.58-2.91

Formation & geological history

Formed through the deposition of silica from water solutions into fissures or volcanic ash, occurring in various geological ages often in association with volcanic activity.

Uses & applications

Commonly used in jewelry (beads, cabochons), protective amulets, decorative carvings, and as a tumbling stone for collectors.

Geological facts

Black Jasper is sometimes known as 'Basanite' and has been historically used as a touchstone to test the purity of gold and silver because of its hardness and dark color.

Field identification & locations

Found worldwide, notably in India, USA, and Africa. Identification features include its smooth, waxy texture and inability to be scratched by a steel knife.