sedimentary

Jasper

Jasper (Silicate - SiO2)

Hardness: 6.5–7 (Mohs scale); Color: Variegated yellow, brown, and red; Luster: Vitreous to waxy; Crystal structure: Microcrystalline (Trigonal); Cleavage: None; Specific gravity: 2.58–2.91

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

Identified April 5, 2026More sedimentary →

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Physical properties

Hardness: 6.5–7 (Mohs scale); Color: Variegated yellow, brown, and red; Luster: Vitreous to waxy; Crystal structure: Microcrystalline (Trigonal); Cleavage: None; Specific gravity: 2.58–2.91

Formation & geological history

Formed from the deposition of silica (silicon dioxide) in environments such as hydrothermal veins or volcanic ash beds. The colors result from iron and other mineral impurities during formation across various geological ages.

Uses & applications

Used primarily for jewelry (cabochons), interior decoration, ornamental stone, and as a popular specimen for rock tumbling and holistic stone collecting.

Geological facts

Jasper is an opaque variety of chalcedony. The name 'jasper' means 'spotted or speckled stone,' derived from the Old French 'jaspre'. It was a favorite gemstone in the ancient world, referenced in the Bible and utilized by the Minoans on Crete.

Field identification & locations

Identify by its opacity (even when held to light), smooth waxy feel, and its inability to be scratched by a steel knife. Commonly found in riverbeds, deserts, and volcanic regions globally (notably Oregon, USA).