Yellow Jasper

Physical Properties

Hardness: 6.5–7 on Mohs scale; Color: Mustard yellow, golden brown; Luster: Vitreous to waxy; Structure: Microcrystalline/Cryptocrystalline quartz; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6–2.9.

Formation & Geological History

Formed through the infiltration of silica-rich fluids into sediment or volcanic ash. The yellow coloration is caused by the inclusion of iron oxide (goethite). It typically occurs in massive configurations in hydrothermal veins or sedimentary beds.

Uses & Applications

Used primarily as an ornamental stone, in jewelry (cabochons and beads), lapidary art, and as a collector's mineral specimen. Historically used for making tools due to its sharp conchoidal fracture.

Geological Facts

Jasper is an opaque form of chalcedony. Yellow jasper was historically believed to provide protection to travelers and was often used in ancient amulets. It is unique in that it is almost always opaque, unlike its relative, agate, which is translucent.

Field Identification & Locations

Identify by its matte to waxy appearance, extreme hardness (it will scratch glass), and its distinctive jasper-yellow fracture surface. Found globally with significant deposits in India, Russia, Brazil, and the USA (California and Oregon).

Identified on: 4/22/2026

Mode: Standard