sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with hydrated iron oxide impurities

Hardness: 6.5-7.0 (Mohs scale); Color: Opaque mustard yellow to golden brown; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.58–2.91

Hardness: 6
Color: Opaque mustard yellow to golden brown
Luster: Vitreous to dull

Identified March 29, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation of silica-rich sediments and volcanic ash, where circulating groundwater introduces iron minerals (like goethite) that provide the yellow pigment. Typically found in secondary deposits like riverbeds as rounded pebbles.

Uses & applications

Used primarily in lapidary arts for cabochons, beads, and pocket stones. Also used in construction as decorative aggregate and in spiritual practices as a 'nurturing' stone.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone'. It was highly prized in the ancient world for both its durability and its ability to take a high polish.

Field identification & locations

Identify by its opaque nature (unlike yellow agate, light won't shine through it), smooth texture, and bright yellow hue. Commonly found in riverbeds and coastal areas globally, particularly in India, Russia, and the USA. Collectors look for uniform color and absence of cracks.

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