sedimentary

Yellow Jasper

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs); Color: Mustard yellow, golden brown, tan; Luster: Vitreous to greasy; Crystal Structure: Microcrystalline/Trigonal; Cleavage: None; Specific Gravity: 2.58-2.91

Hardness: 6
Color: Mustard yellow, golden brown, tan
Luster: Vitreous to greasy

Identified May 9, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Mustard yellow, golden brown, tan; Luster: Vitreous to greasy; Crystal Structure: Microcrystalline/Trigonal; Cleavage: None; Specific Gravity: 2.58-2.91

Formation & geological history

Formed through the deposition of silica from water solutions or volcanic ash, followed by cementation over millions of years. Its yellow hue is caused by high iron (goethite) content.

Uses & applications

Used primarily for ornamental purposes, lapidary arts, jewelry (cabochons and beads), and as a collector's decorative sphere.

Geological facts

Jasper is an opaque variety of chalcedony. Yellow Jasper was historically used as a 'stone of protection' for travelers and is often found in large nodules or beds.

Field identification & locations

Identify by its opaque nature, smooth waxy surface when polished, and distinctive mustard-yellow mottling. Common in South Africa, Madagascar, and the USA.