Characteristic minerals are milky white quartz, chalcopyrite, pyrrhotite, sphalerite, and galena, along with minor pyrargyrite
, sericite, and chlorite.
stockwork in siderite and quartz-encrusted cavities, together with acanthite, native silver, barite, kaolinite, and museum-quality specimens of polybasite and stephanite were noted (Jeff Franzen and Ken Watson, pers.
Soon he began shipping some extraordinary silver mineral specimens back to New York, including the largest and best polybasite specimens known, large clusters of "poker chip" stephanite crystals, fine acanthite specimens and a few very fine pyrargyrite
In recent years the Fresnillo area has produced remarkable examples of the silver sulfosalts pyrargyrite
, stephanite and polybasite.
During the 1890s and the first few years of the 20th century the Las Chispas mine near Arizpe produced some of the world's finest specimens of polybasite, pyrargyrite
A spectacular cabinet-size pyrargyrite
crystal cluster from Hartenstein, Saxony rounds out the silver minerals suite.
The Crown Crescent lode in the Emperor mine has yielded very minor amounts of bournonite, pyrargyrite
, proustite and polybasite.
The main sulfide minerals are pyrite, galena, sphalerite and chalcopyrite, and much less commonly tetrahedrite and silver sulfosalts (pyrargyrite
, proustite and polybasite).
In some cases the rhodochrosite is covered by hemispherical aggregates of black sphalerite to 3 cm in diameter, accompanied by small pyrite and rarely even tiny pyrargyrite
Similar-looking specimens are sometimes labeled proustite, sometimes pyrargyrite
They're all here, in multiple samples ranging in quality from "study grade" to absolutely superb: Freiberg acanthite and stephanite, Schneeberg proustite and erythrite and roselite and uranium-bearing species, Andreasberg pyrargyrite
and dyscrasite and fluorite and pink apophyllite, Siegerland malachite and anglesite and millerite and galena, Schwarzwald fluorite and barite and silver, Obermoschel cinnabar and moschellandsbergite, Ems pyromorphite and cerussite, Johanngeorgenstadt mimetite, Ohrenstock hausmannite, Fichtelgebirge topaz and microcline and herderite, Ehrenfriedersdorf cassiterite and fluorapatite, Ilfeld manganite, Ronneburg whewellite, Hagendorf phosphates ...
Rob Lavinsky reports a discovery of yet more superb pyrargyrite
specimens at Fresnillo, Zacatecas, Mexico: a few pieces with transparent blood-red pyrargyrite
crystals to several centimeters across rising from massive white calcite came, in July 2006, from the 450 level on the San Carlos vein.