Green Chalcedony (likely Chrysoprase or Green Onyx)

Physical Properties

Hardness: 6.5-7 (Mohs scale). Color: Apple-green to deep emerald green. Luster: Vitreous to waxy. Crystal Structure: Hexagonal (trigonal) cryptocrystalline. Cleavage: None (conchoidal fracture). Specific Gravity: 2.6-2.64.

Formation & Geological History

Formed in the cracks and cavities of basalt and other volcanic rocks, or as secondary deposits in weathered serpentinites and other nickeliferous rocks. It forms via the cooling of silica-rich groundwater.

Uses & Applications

Primarily used in jewelry (cabochons, beads, rings), ornamental carvings, and as a semi-precious collector stone.

Geological Facts

Chrysoprase is the most valuable variety of chalcedony. In ancient times, the Greeks and Romans used it for seals and cameos. It is often mistaken for jade due to its similar color and translucency.

Field Identification & Locations

Identify by its waxy luster and solid, even green color (unlike emerald, which often has visible inclusions). Commonly found in Australia, Brazil, Russia, and the USA (California/Arizona). It is more translucent than jasper.

Identified on: 4/15/2026

Mode: Standard