sedimentary

Jasper

Silicon dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7.0 (Mohs scale); Color: Red, brown, or earthy tones; Luster: Dull to vitreous; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific gravity: 2.58-2.91.

Hardness: 6
Color: Red, brown, or earthy tones
Luster: Dull to vitreous

Identified June 27, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7.0 (Mohs scale); Color: Red, brown, or earthy tones; Luster: Dull to vitreous; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific gravity: 2.58-2.91.

Formation & geological history

Formed through the infiltration of silica-rich fluids into volcanic ash or fine sedimentary material, often colored by iron oxide. It typically dates from the Proterozoic to Cenozoic eras.

Uses & applications

Commonly used in jewelry (cabochons), ornamentation, lapidary arts, and as a collector's stone. Historically used for seal stones and tools.

Geological facts

Jasper is an opaque variety of chalcedony. The name is derived from the Greek 'iaspis', meaning 'spotted stone'. It was one of the stones used in the Breastplate of Aaron.

Field identification & locations

Identify in the field by its waxy-to-dull luster, opacity, and conchoidal fracture. Often found as rounded pebbles in stream beds or coastal beaches where water has polished them.