Bismuth tellurides (joseite-B, bismuthian tsumoite) in a Pb-Zn deposits from Tunaberg, Sweden

Joseite-B (Bi (sub 4.08-4.14) Pb (sub 0.02-0.03) Sb (sub 0.00- 0.04) ) (sub 4.10-4.16) (Te (sub 1.85-2.01) S (sub 0.83-1.05) ) (sub 2.84- 2.90) and bismuthian tsumoite (Bi (sub 1.11-1.40) Te (sub 0.54- 0.82) Pb (sub 0.01-0.02) Sb (sub 0.00-0.09) S (sub 0.00-0.03) ) from Tunaberg, Bergslagen, central Sweden, occur in composite grains and in trails with native bismuth in galena-rich samples. The mineral textures suggest contemporaneous crystallization of the Bi minerals with the galena host, probably from Pb-Bi-Te-rich skarn- forming ore fluids. The cooling of Bi-Te-rich fluids below 350 degrees C may have crystallized the bismuthian tsumoite, which coexists with native bismuth only below 266 degrees C.