Images
Formula: AgPbBi3S6
Sulphosalt, lillianite homologous series group,
forms a series with lillianite,
silver- and bismuth- bearing mineral
Crystal System: Orthorhombic
Specific gravity: 7.01 calculated
Hardness: 3½
Streak: Grey
Colour: Steel-grey
Common impurities: Sb
Environments
Pegmatites
Hydrothermal environments
Gustavite is a rare mineral of hydrothermal origin that also occurs in
pegmatites. Associated minerals include
aikinite, bismuthinite,
cosalite, pavonite,
benjaminite, bismuth,
chalcopyrite, tetrahedrite,
pyrrhotite, stannite and
arsenopyrite
(HOM).
Localities
At the Tanco mine, Bernic Lake, Lac-du-Bonnet area, Manitoba, Canada, the
pegmatite deposit is mined for
tantalum oxide minerals, but it also contains refractory-grade
spodumene and the world's largest known concentration of
pollucite. Rare occurrences of sulphide minerals have been encountered,
including gustavite, that occurs in grains up to 2 mm in size associated with
aikinite-bismuthinite
intergrowths, cosalite, native
bismuth, chalcopyrite,
tetrahedrite, pyrrhotite,
stannite and arsenopyrite
(CM 13.411-414).
At the Silver Bear mine, Camsell River area, Northwest Territories, Canada, the deposit is a
silver-rich ore in which two distinct mineral assemblages, one sulphide and
one arsenide, are evident. The sulphide assemblage consists mainly of
pyrite, chalcopyrite,
sphalerite, galena and
tetrahedrite, whereas the
arsenide assemblage, which is more complex, consists mainly of
nickeline, safflorite,
skutterudite,
rammelsbergite,
arsenopyrite, native silver,
native bismuth, bismuthinite,
matildite, gustavite,
acanthite and a pavonite-type
mineral. Gustavite is rare in the ore and occurs as inclusions (up to 200 microns) in the cores of
arsenide rosettes associated with
bismuthinite, matildite and
the pavonite-type mineral
(CM 13.411-414).
At the type locality, the Ivigtut mine, Arsuk Fjord, Sermersooq, Greenland, gustavite occurs as grains,
tabular in form and sometimes slightly bent. Maximum grain size is 2 x 2 x 0.5 mm.
Associated Minerals include galena and
berryite
(Mindat).
Back to Minerals