sedimentary

Jasper

Silicon dioxide (SiO2) with impurities

Hardness: 6.5-7.0 (Mohs); Color: Brown, red, or multi-colored with banding; Luster: Vitreous to waxy (especially when polished); Crystal Structure: Microcrystalline/cryptocrystalline (Trigonal); Cleavage: None; Specific Gravity: 2.58-2.91

Hardness: 6
Color: Brown, red, or multi-colored with banding
Luster: Vitreous to waxy (especially when polished)

Identified June 3, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica from water or hydrothermal fluids into voids or as a replacement mineral in sedimentary environments, often involving volcanic ash or organic matter that provides the pigment.

Uses & applications

Used primarily in lapidary work, jewelry (beads, cabochons), ornamental decoration, and as a healing stone in metaphysical practices.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Old French word 'jaspre', meaning 'spotted or speckled stone'. It has been used for talismans and tools since Neolithic times.

Field identification & locations

Identify in the field by its high hardness (will scratch glass), opaque nature, and conchoidal fracture. Often found in riverbeds or coastal gravels where water has tumbled it smooth over time.