man-made glass
Blue Goldstone
Aventurine glass (Synthetic borosilicate glass with cobalt and metallic inclusions)
Hardness: 5.5-6.0 Mohs; Color: Deep midnight blue with sparking silver/blue metallic inclusions; Luster: Vitreous; Crystal Structure: Amorphous (glass); Cleavage: None (conchoidal fracture); Specific Gravity: 2.5
- Hardness
- 5
- Luster
- Vitreous
Identified More man-made glass →
Explore Blue Goldstone in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5.5-6.0 Mohs; Color: Deep midnight blue with sparking silver/blue metallic inclusions; Luster: Vitreous; Crystal Structure: Amorphous (glass); Cleavage: None (conchoidal fracture); Specific Gravity: 2.5
Formation & geological history
Created in a low-oxygen reducing atmosphere furnace where cobalt is added for the blue color and metallic flakes (often copper or manganese) are suspended in the cooling glass molten. While modern production is commercial, the process dates back to 17th-century Venice.
Uses & applications
Primarily used for jewelry (pendants, beads, rings), decorative figurines, palm stones for meditation, and costume accessories.
Geological facts
Despite its name, Goldstone contains no gold. It is often misidentified as a natural mineral like Lapis Lazuli or Blue Sandstone, but it is a glass. Legend says it was discovered by accident by Italian monks, but the recipe likely originated with the Miotti family of Venice.
Field identification & locations
Identify by its perfectly uniform distribution of 'glitter' flakes which do not occur naturally in this patterns in earth-mined stones. It is not found in nature; it is manufactured in factories. For collectors, it is valued for its 'aventurescence' (shimmering effect).
More like this
Other man-made glass specimens
Opalite
Man-made Glass (SiO2 + additives)
mineraloid (synthetic)
Opalite
Man-made Glass (Synthetic Opalized Glass)
mineral
Opalite
Man-made glass (traditionally simulated Opal)
mineral
Dragon's Breath (Mexican Opal Glass)
Artisan Foil Glass (SiO2 based)
mineraloid
Opalite (Man-made Glass)
Synthetic Silicon Dioxide Glass (SiO2 + metal oxides)
Synthetic Mineral Simulant / Glass
Opalite (Man-made Glass)
Synthetic Opalised Glass
mineral