sedimentary

Jasper

Jasper (Silicon Dioxide, SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Red, brown, yellow; Luster: Vitreous to greasy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Red, brown, yellow
Luster: Vitreous to greasy

Identified June 7, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Red, brown, yellow; Luster: Vitreous to greasy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Formation & geological history

Formed from silica-rich groundwater percolating through sedimentary or volcanic ash deposits, often during the Proterozoic to Cenozoic eras. The red color is caused by iron oxide inclusions.

Uses & applications

Widely used in jewelry (cabochons, beads), decorative ornaments, stone carvings, and as a popular lapidary material for collectors.

Geological facts

Jasper is a variety of chalcedony. Historically, it was known as the 'supreme nurturer' and has been used by ancient civilizations for amulets and seals for thousands of years.

Field identification & locations

Identify in the field by its opaque nature (unlike translucent agate), conchoidal fracture, and inability to be scratched by a steel knife. Common in the Western US, India, and Brazil.