Yellow Jasper

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Mustard yellow to golden brown; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.58–2.91

Formation & Geological History

Formed from the deposition of silica from water solutions into fissures or cavities in other rocks. Its yellow color comes from high concentrations of iron oxide (goethite) inclusions. It can be found in a variety of geological ages but often appears in regions with volcanic or hydrothermal activity.

Uses & Applications

Primarily used for ornamental purposes including lapidary work (cabochons, beads), jewelry, pocket stones, and decorative carvings. It is also a popular specimen for rock collectors.

Geological Facts

Jasper is an opaque variety of chalcedony. The name 'jasper' is derived from the Greek 'iaspis', meaning 'spotted stone.' Yellow jasper was traditionally used by indigenous cultures as a protective talisman during travel.

Field Identification & Locations

Identify by its rich yellow color, extreme hardness (can scratch glass), and smooth, waxy surface when polished. Unlike citrine, it is completely opaque. Found commonly in South Africa, Brazil, India, and the USA (notably Oregon and Idaho).

Identified on: 4/21/2026

Mode: Standard