sedimentary

Black Jasper

Silicon Dioxide (SiO2) with impurities

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Black with occasional white or grey veining; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.6-2.9.

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

Identified June 25, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Black with occasional white or grey veining; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.6-2.9.

Formation & geological history

Formed through the deposition of silica from water into cavities or via the replacement of organic or volcanic materials. Found often in hydrothermal veins or sedimentary environments across many geological ages.

Uses & applications

Used primarily as a gemstone for jewelry, in lapidary arts for decorative carvings, and as a popular stone for tumbling and collecting.

Geological facts

Also known as Blackstone or Basanite (historically used as a touchstone to test for gold and silver quality). Jasper is the dense, opaque form of chalcedony.

Field identification & locations

Identify by its hardness (cannot be scratched by a steel knife), opaque density, and smooth, conchoidal fracture. Commonly found in riverbeds or coastal areas where quartz-rich minerals accumulate.