sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides (Goethite or Limonite)

Hardness: 6.5-7 (Mohs scale), Color: Mustard yellow to golden brown, Luster: Dull to waxy, Crystal structure: Microcrystalline/Cryptocrystalline (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.58–2.91

Hardness: 6

Identified March 21, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the deposition of silica-rich fluids in volcanic ash or sedimentary basins. Its mustard yellow hue is typically caused by inclusion of goethite (hydrated iron oxide). It can range from millions to hundreds of millions of years in age depending on the deposit.

Uses & applications

Used primarily in lapidary arts for cabochons, beads, and decorative carvings. Industrially used as an abrasive or in minor construction fill, and highly valued in spiritual 'crystal healing' communities.

Geological facts

Jasper is an opaque variety of chalcedony. The name 'jasper' comes from the Greek 'iaspis', meaning 'spotted stone.' Yellow jasper was traditionally used as a stone of protection and travelers' luck.

Field identification & locations

Identify in the field by its opacity (does not let light through, unlike agate), smooth water-worn texture on beaches, and extreme hardness—it will easily scratch a glass bottle or steel knife. Common in riverbeds and along Pacific Northwest coastlines.

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