Blue Goldstone
Aventurine Glass
Rock Type: Man-made glass (often grouped with minerals in lapidary)

Physical Properties
Hardness: 5.5-6 (Mohs scale); Color: Deep midnight blue with vibrant blue or violet sparkles; Luster: Vitreous (glassy); Crystal Structure: Amorphous (non-crystalline glass); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.5-2.8
Formation & Geological History
Goldstone is a synthetic glass created in a low-oxygen reducing atmosphere. It was originally discovered in 17th-century Venice by the Miotti family. The blue variety is created by adding cobalt or manganese to the silica melt, which causes the metallic copper or other metal oxides to crystallize into tiny flakes.
Uses & Applications
Primarily used for decorative purposes, jewelry (pendants, beads, cabochons), carving small figurines, and as a popular stone for crystal healing and collector sets.
Geological Facts
Despite its name, it contains no gold. Its 'glitter' comes from the inclusion of tiny metallic crystals. While man-made, it is treated as a gemstone in the lapidary world and has been produced for centuries.
Field Identification & Locations
Identify by its uniform, intense sparkling effect (aventurescence) and smooth, glass-like surface. It will not be found in nature; it is always the result of human manufacturing. Look for the characteristic conchoidal (shell-like) fracture if chipped.
Identified on: 4/20/2026
Mode: Standard