mineral
Goldstone (blue/black aventurine glass)
Man-made aventurine glass; silica glass containing metallic copper or other glittering inclusions
AI-generated identification · may be incorrectPolished, opaque dark blue-black sphere with abundant copper-colored sparkles and glassy luster; hardness about 5.5–6 Mohs, conchoidal fracture, no cleavage, and specific gravity roughly 2.4–2.6. The uniform glitter and perfectly rounded polish indicate manufactured glass rather than natural rock.
Identified More mineral →
Explore Goldstone (blue/black aventurine glass) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Polished, opaque dark blue-black sphere with abundant copper-colored sparkles and glassy luster; hardness about 5.5–6 Mohs, conchoidal fracture, no cleavage, and specific gravity roughly 2.4–2.6. The uniform glitter and perfectly rounded polish indicate manufactured glass rather than natural rock.
Formation & geological history
Produced by cooling molten glass containing metal oxide particles, which crystallize into reflective inclusions; it is human-processed and has no geological age in the natural-rock sense. Blue varieties commonly use cobalt or other colorants, while classic goldstone uses copper.
Uses & applications
Used for cabochons, beads, spheres, carvings, jewelry, and decorative objects. Commonly marketed as “blue sandstone” or “blue goldstone,” though it is not sandstone.
Geological facts
Its sparkle comes from light reflecting off tiny metallic crystals, not from natural quartz. Italian aventurine glass is historically associated with Murano glassmaking.
Field identification & locations
Identify by consistent glitter throughout, glassy smoothness, rounded bubbles or flow textures, and lack of natural grain; natural stones rarely show such evenly distributed flash. Commonly sold from Chinese and Italian glass workshops.
