mineral

Goldstone (blue/black aventurine glass)

Man-made aventurine glass; silica glass containing metallic copper or other glittering inclusions

AI-generated identification · may be incorrect

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.

Identified August 23, 2026More mineral →

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Physical properties

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.