The new mineral occurs within a cavity in a massive tennantite
sample (4 X 5 X 7 cm) from the Tsumeb mine at Tsumeb, Namibia.
The pseudomorphs are intergrown with quartz prisms, tennantite
crystals to 1 cm, and black sphalerite crystals to 3 cm covered by tiny tennantite
Beautiful crystals of chalcopyrite are rather rare in the deposit, despite the production of 2,000 tonnes/year of copper concentrates at Trepca (copper in the ore is contained in chalcopyrite, pyrrhotite, tetrahedrite, tennantite
, bournonite, bornite and enargite).
Any of the rarer species from Silvermines such as jordanite, proustite, tennantite
There, it is associated with cinnabar, native mercury, sphalerite, tennantite
, chalcopyrite, polydymite and pyrite.
Occurrence: In the oxidized zone in a "nest" consisting of galena, tetrahedrite and tennantite
in a quartz vein.
The Smithsonian filled a case with fine Tsumeb minerals including leadhillite, anglesite, tennantite
, azurite, smithsonite and other collector species.
We have only observed the primary species chalcopyrite and tennantite
([[Cu.sub.9.48][Fe.sub.1.50][Ag.sub.0.92] [Zn.sub.0.32]]-[[As.sub.3.56][Sb.sub.0.25][P.sub.0.05]][S.sub.13]) for a total of 99.48 percent of the weight, in a La Atalaya specimen.
(X-ray verified) crystals to 5 cm were found in 2002, some of them partially covered by green scorodite.
Freibergite is a rare member of the tetrahedrite group in which silver predominates over copper and iron in the cation sites; good crystals have always been rare, and must in any case be analytically verified as freibergite, as they cannot be visually distinguished from tetrahedrite or tennantite
. The new freibergites from a discovery late last summer in the famous Herja mine, Maramures, Rommia have been so verified, and about 50 small-thumbnail-sized specimens were brought to Tucson this year by Ross billie of North Star Minerals.
World-class-caliber specimens of many species have been found at Peruvian sites in the last few decades, including pyrite, sphalerite, galena, chalcopyrite, tetrahedrite, tennantite
, hubnerite, fluorite, rhodochrosite, gypsum, atacamite, quartz, epidote, rhodonite and silver.