mineral
Aventurine
Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)
Hardness: 6.5-7 Mohs; Color: Green; Luster: Vitreous to waxy; Crystal structure: Trigonal; Cleavage: None; Specific Gravity: 2.64-2.69. Known for aventurescence (a glistening effect).
- Hardness
- 6
- Color
- Green
- Luster
- Vitreous to waxy
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Physical properties
Hardness: 6.5-7 Mohs; Color: Green; Luster: Vitreous to waxy; Crystal structure: Trigonal; Cleavage: None; Specific Gravity: 2.64-2.69. Known for aventurescence (a glistening effect).
Formation & geological history
Forms in metamorphic rocks like phyllites and schists where silica-rich fluids cool or where quartz undergoes metamorphism alongside mica minerals like fuchsite.
Uses & applications
Primarily used for jewelry, lapidary art, carvings, beads, and as a popular stone for crystal collecting and metaphysical purposes.
Geological facts
The name comes from the Italian 'a ventura', meaning 'by chance', originally referring to an 18th-century accidental discovery of aventurine glass. The dark green specimen here likely contains higher concentrations of chromium-rich mica.
Field identification & locations
Identify by its characteristic green color and 'sparkly' interior reflections (aventurescence) when turned under light. Commonly found in India, Brazil, and Russia.
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