sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) - Microcrystalline Quartz

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Mustard yellow, yellowish-brown, golden brown; Luster: Waxy to dull; Crystal structure: Trigonal/Microcrystalline; Cleavage: None, exhibits conchoidal fracture; Specific gravity: 2.58-2.91

Hardness: 6
Color: Mustard yellow, yellowish-brown, golden brown
Luster: Waxy to dull

Identified July 22, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when fine silica-rich fluids permeate sediments, volcanic ash, or clay, accumulating iron oxide (goethite/limonite) impurities that give it its yellow color.

Uses & applications

Used for making cabochons, lapidary carvings, tumbled stones, decorative ornaments, and widely collected as a semi-precious gemstone.

Geological facts

Yellow jasper has been used since antiquity for seals and amulets. Its yellow hue is mainly due to the presence of hydrated iron oxide minerals mixed in the silica matrix.

Field identification & locations

Look for a dense, opaque microcrystalline texture with a smooth waxy luster and conchoidal fracture. Found in stream beds, volcanic regions, and sedimentary deposits globally including Brazil, India, Madagascar, and the USA.