Crystal System: Hexagonal
Status of Occurrence: Confirmed Occurrence
Chemical Composition: Lead antimony sulphosalt
Chemical Formula: Pb9Sb22S42
Method(s) of Verification: Bwlch Mine - EMPA & XRD (Bevins, et.al., 1988, University College, Cardiff).
- Hydrothermal: epithermal polymetallic veins & pipes
Introduction: zinkenite occurs with stibnite, galena and various lead-antimony sulphosalts in complex hydrothermal vein and breccia assemblages typical of the epithermal Pb-Sb association.
Occurrence in Wales: the only record of zinkenite from Wales is that which resulted from investigations of the antimony mineralization at Bwlch Mine near Deganwy on the North Wales coast (Bevins et al., 1988). As with many of the Pb-Sb sulphosalts, it is difficult to identify positively in hand specimen and consequently, verification often requires detailed analytical techniques.
- Bwlch Mine, Deganwy, Gwynedd: zinkenite occurs intergrown with other Pb-Sb sulphosalts (especially semseyite and plagionite) and with stibnite in small (< 2 cm) patches and stringers associated with quartz in a stockwork-like group of veins hosted by altered spherulitic acid ash-flow tuff (Bevins et al., 1988). The latter authors state that it 'appears to be more common than semseyite'.
- Bevins, R.E., Alderton, D.H.M. & Horak, J.M., 1988. Lead-antimony mineralisation at Bwlch Mine, Deganwy, Wales. Mineralogical Magazine, 52, 391-394.