Hackmanita
Hackmanita is a mineral with formula Na₈(Al₆Si₆O₂₄)Cl₂, in the Silicatos (Tectosilicatos) group. This specimen comes from Badakhshan, Afganistán.
Description
Irregular light blue and creamy white mass, with lavender zones and small dark specks. Granular texture, with some parts slightly translucent. Tenebrescent, phosphorescent and fluorescent: under UV light it fluoresces intense orange, and the lavender zones shift to deep purple after one minute of exposure.
About Hackmanita
Hackmanite is a sulphur-rich sodalite known for its tenebrescence, fluorescence and phosphorescence. Tenebrescence occurs because UV light temporarily alters some defect centres in its crystal structure. Under ultraviolet radiation certain electrons shift position and the mineral begins to absorb light differently, turning lavender areas a deep purple. Over time, in normal light or darkness, those electrons gradually return to their original state and the colour fades again. Unlike fluorescence, it does not just "glow": it actually changes colour for a time.
About the locality
Badakhshan is a classic Afghan region for coloured minerals and alkaline rocks. Provenance usually reaches the market generically, without a specific mine, but the material is notable for tenebrescent hackmanite, often associated with sodic minerals such as winchite.
Technical data
- Catalogue No.
- 0624
- Internal reference
- X0334
- Composition
- Na₈(Al₆Si₆O₂₄)Cl₂
- Name
- Hackmanita
- Group
- Silicatos (Tectosilicatos)
- Category
- Lucimera
- Associations
- winchita
- Province
- Badakhshan
- Country
- Afganistán
- Size (cm)
- 3 x 2 x 1.5
- Weight
- 30 g
- Etymology
- Named in honour of Victor Hackman. Winchite honours Howard J. Winch, an English electrical engineer.
- Quality
- Buena
- Value trend
- Estable