Pyrargyrite


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pyrargyrite

[pī′rär·jə‚rīt]
(mineralogy)
Ag3SbS3 A deep ruby-red to black mineral, crystallizing in the hexagonal system, occurring in massive form and in disseminated grains, and having an adamantine luster; hardness is 2.5 on Mohs scale, and specific gravity is 5.85; an important silver ore. Also known as dark-red silver ore; dark ruby silver.

Pyrargyrite

 

a mineral with composition Ag3SbS3, containing 59.76 percent Ag, 22.48 percent Sb, and 17.76 percent S. Pyrargyrite crystallizes in the trigonal system. It occurs as irregularly shaped grains and their aggregates and in the form of prismatic crystals. It is dark red, with an adamantine luster. A brittle mineral, it has a hardness of 2.5 on Mohs’ scale and a density of 5,770–5,860 kg/m3.

Pyrargyrite is not a widely occurring mineral. It forms in hydrothermal deposits at moderate or low temperatures. In the USSR, deposits are found in the Urals, Middle Asia, Transbaikalia, the Yakut ASSR, and the Far East. Other deposits are found in the German Democratic Republic, the Federal Republic of Germany, Czechoslovakia, Mexico, Chile, and Bolivia. Along with other silver-bearing minerals, pyrargyrite is an important ore of silver.

References in periodicals archive ?
Pyrargyrite 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 specimens.
In recent years the Fresnillo area has produced remarkable examples of the silver sulfosalts pyrargyrite, stephanite and polybasite.
Since then Fresnillo has become one of the world's greatest silver districts, and has also yielded superb specimens of crystallized pyrargyrite, stephanite, acanthite and polybasite.
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.
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.
He also got apophyllite and valencianite from Guanajuato, and had spent a week in Zacatecas (10) buying specimens of proustite, pyrargyrite, stephanite and native silver.
In the late 1990's, a galena vein with minor pyrargyrite was worked in neighboring Uncia, on the southeast side of the mountain, and it is possible that such veins were found extensively during the early 19th century but have been obliterated by mining.