Crystal System: Trigonal
Status of Occurrence: Confirmed Occurrence - 1st UK recording
Chemical Composition: Bismuth telluride
Chemical Formula: Bi4Te3
Method(s) of Verification: Clogau Mine - 'wehrlite' revealed by EMPA (Naden, 1988).
- Hydrothermal: mesothermal polymetallic veins
Introduction: pilsenite occurs in complex bismuth telluride assemblages typically associated with gold deposits.
Occurrence in Wales: the presence of 'wehrlite' was recorded in galena dominated gold-bearing veins at Clogau Mine by Naden (1988). However it has been shown that 'wehrlite' is not a valid mineral species but is instead intimately intergrown pilsenite and hessite (Ozawa & Shimazaki, 1982). Thus, by default, pilsenite found its way onto the Welsh mineral species list.
- Clogau Mine, Bontddu, Gwynedd: intergrowths of pilsenite with hessite occur as grains which were identified by Naden (1988) as the subsequently discredited species wehrlite.
- Naden, J., 1988. Gold mineralisation in the Caledonides of the British Isles with reference to the Dolgellau Gold Belt and the Southern Uplands of Scotland. Unpublished Ph.D thesis, University of Aston, UK.
- Ozawa, T. & Shimazaki, H., 1982. Pilsenite redefined and wehrlite discredited. Proceedings of the Japanese Academy, 58, 291.