sedimentary

Jasper

Silicon dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs scale); Color: Brownish-red to ochre; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.9

Hardness: 6
Color: Brownish-red to ochre
Luster: Vitreous to dull

Identified June 7, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Brownish-red to ochre; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.9

Formation & geological history

Formed through the deposition of silica from water solutions or volcanic ash, occurring within hydrothermal veins or as nodules in sedimentary rocks. Can range from Precambrian to recent ages.

Uses & applications

Commonly used as a gemstone, in lapidary work for cabochons and beads, as an ornamental stone in carvings, and historically used for making stone tools due to its sharp fracture.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek 'iaspis', meaning 'spotted stone'. In ancient times, it was considered a powerful protective stone.

Field identification & locations

Identify by its opacity (unlike translucent agate), waxy luster, and conchoidal fracture. Found worldwide, notably in the USA, Brazil, India, and Africa. Collectors look for unique banding or patterns.