Hodrušite

hodrusite

chalcopyrite

pavonite

wittichenite

Images

Formula: Cu8Bi12S22
Sulphosalt, bismuth-bearing mineral
Specific gravity: 6.35 measured, 6.451 calculated
Hardness: 4 to 5
Streak: Greyish black
Colour: Steel-grey with slight yellowish tint, tarnishes to brownish bronze
Environments

Pegmatites
Hydrothermal environments

Localities

At the Szklarska Poręba Huta granite quarry, Szklarska Poręba, Karkonosze County, Lower Silesian Voivodeship, Poland, small bodies of granitic pegmatite are common within the coarsely crystalline variety of the granite. In addition to minerals typical of granitic pegmatites, they contain magnetite, ilmenite, hematite, titanite, zircon, xenotime, monazite, thorite, thorogummite, yttrialite, davidite, beryl, gadolinite-(Y), gadolinite-(Ce), hingganite-(Y), epidote, allanite, pumpellyite-(Mg), pumpellyite-(Fe), clinochlore, chamosite, laumontite, chabazite, stilbite, ferberite-hübnerite, scheelite, cassiterite, molybdenite, base-metal sulphides, emplectite, nuffieldite, native bismuth, some supergene minerals, and an assemblage of newly recognised bismuth sulphosalts.
A sulphide assemblage, accompanying minor wolframitescheelitecassiterite mineralisation, crystallised from late-circulating aqueous fluids in voids within the granite, and less frequently in typical granitic pegmatite in the vicinity. Besides those non-sulphide minerals, other minerals present in the assemblage include molybdenite, pyrrhotite, pyrite, chalcopyrite, sphalerite, emplectite, nuffieldite, bismuthinite, marcasite and native bismuth, as well as traces of chalcocite, covellite and malachite as common supergene phases.
Where the samples containing hodrušite were collected, the granite itself, as well as walls of the cavities, is in some cases mineralised with wolframite, scheelite and sulphides, mainly pyrite, chalcopyrite and molybdenite; the same minerals are found along with bismuthinite and native bismuth in thin quartz veinlets cutting the granite. Emplectite and other bismuth sulphides, such as aikinite, friedrichite, krupkaite, gladite, pekoite, kupčikite, hodrušite, cuprobismutite, galenobismutite, cannizzarite, cosalite, ikunolite, joséite-A, as well as bismite, bismutite, powellite, koechlinite(?) and russellite as supergene phases, are less frequent in the assemblage.
Lamellar intergrowths of kupčikite with hodrušite, and more infrequently hodrušite with cuprobismutite, have been observed in all the grains studied from Szklarska Poręba. It appears that cuprobismutite exists in the sulphide assemblage only as nm-scale intergrowths with hodrušite (CM 50.313-324).

At the type locality, the Hodruša-Hámre mines, Hodruša-Hámre, Žarnovica District, Banská Bystrica Region, Slovakia, hodrušite was found In a polymetallic ore deposit of subvolcanic type, in a quartz vein system developed in altered pyroxenite andesite, associated with quartz and hematite, and locally with chalcopyrite, pavonite and wittichenite(?). It forms needle shaped crystals less than 1 mm in length, irregular grains, or fine-grained aggregates. Occasionaliy, columnar and platy crystals up to 5 mm long are found. These are striated vertically (AM 56.633, HOM).

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