Yellow Jasper

Physical Properties

Hardness: 6.5-7 on Mohs scale; Color: Mustard yellow to brownish-yellow; Luster: Dull to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9

Formation & Geological History

Formed through the deposition of silica from water-saturated solutions, often in volcanic or sedimentary environments. The yellow color results from the inclusion of iron hydroxides like goethite.

Uses & Applications

Used primarily as a lapidary material for jewelry (cabochons, beads), decorative carvings, and as a popular specimen for rock tumbling and metaphysical collections.

Geological Facts

Jasper is an opaque variety of chalcedony. It has been used by ancient civilizations for amulets and seals; the name is derived from the Greek 'iaspis', meaning spotted stone.

Field Identification & Locations

Identify in the field by its opacity (it does not transmit light even on thin edges), its smooth rounded surface if found in riverbeds, and its high hardness which prevents scratching by a steel knife. Common in riverbeds and desert environments globally.

Identified on: 4/17/2026

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