sedimentary

Jasper

Silicon Dioxide (SiO2)

Hardness: 6.5 - 7 (Mohs scale); Color: Variegated red, yellow, and brown; Luster: Vitreous to dull; Crystal structure: Hexagonal (cryptocrystalline); Cleavage: None; Specific gravity: 2.58 - 2.91

Hardness: 6
Color: Variegated red, yellow, and brown
Luster: Vitreous to dull

Identified March 10, 2026More sedimentary →

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Physical properties

Hardness: 6.5 - 7 (Mohs scale); Color: Variegated red, yellow, and brown; Luster: Vitreous to dull; Crystal structure: Hexagonal (cryptocrystalline); Cleavage: None; Specific gravity: 2.58 - 2.91

Formation & geological history

Formed through the deposition of silica in hydrothermal veins or as replacement material in sedimentary rocks. Colors are derived from mineral inclusions like iron oxides. Ancient geological ages vary by location.

Uses & applications

Used primarily in lapidary arts for jewelry, beads, and cabochons, as well as decorative items and as an abrasive in specific industrial applications.

Geological facts

Jasper has been used as a gemstone since antiquity; it was frequently used in the ancient world for cylinder seals and amulets. It is an opaque variety of chalcedony.

Field identification & locations

Identify by its opacity (it does not transmit light), conchoidal fracture, and smooth, waxy feel when polished. Commonly found in riverbeds or volcanic ash areas. Collectors look for unique patterns or banding.