sedimentary

Jasper

Silicon dioxide (SiO2)

Hardness: 6.5-7 (Mohs); Color: Mottled green, grey, and dark brown; Luster: Vitreous to waxy (when polished); Crystal structure: Microcrystalline/Cryptocrystalline trigonal; Cleavage: None; Specific gravity: 2.58-2.91

Hardness: 6
Color: Mottled green, grey, and dark brown
Luster: Vitreous to waxy (when polished)

Identified June 30, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica from water-rich environments, often associated with volcanic ash or sedimentary beds. The color variations result from mineral inclusions like iron oxides or clay particles trapped during consolidation.

Uses & applications

Commonly used for tumbled stones, decorative ornaments, cabochons for jewelry, 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 centuries across many cultures for amulets and tools.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), its opaque nature, and smooth conchoidal fracture. Often found as rounded pebbles in stream beds or coastal areas.