- Argyrodite
Infobox mineral
name = Argyrodite
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formula =silver germanium sulfide :Ag8GeS6
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color = Black, purplish tinge
habit = tetrahedron or rhombic dodecahedron
system =Orthorhombic
twinning =
cleavage = absent
fracture = Conchoidal
mohs = 2.5
luster = metallic
refractive = opaque
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gravity = 6.2-6.5
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other =Argyrodite, silver germanium sulfide Ag8GeS6 is relatively scarce mineral. The colour is iron-black with a purplish tinge, and the lustre metallic.
Discovered by
Clemens Winkler in 1886 it is of interest as it was described shortly after the elementgermanium was isolated, 15 years after it had been postulated byMendeleev . It occurs in the Himmelsfürst Mine,Freiberg ,Saxony and inBolivia .It is of interest to note that the Freiberg mineral was long ago imperfectly described by
August Breithaupt under the name Plusinglanz, and that the Bolivian crystals were incorrectly described in 1849 as crystallizedbrongniardite .Isomorphous with argyrodite is the corresponding
tin bearing mineral Ag8SnS6, also found in Bolivia as pseudocubiccrystals , and known by the namecanfieldite . There is also a related mineral,putzite , with composition (Cu4.7Ag3.3)GeS6.Argyrodite gets its name from the Greek words that loosely translate into "rich in
silver ".References
* [http://www.mindat.org/min-331.html MinDat]
* [http://mineral.galleries.com/minerals/sulfides/argyrodi/argyrodi.htm Mineral Galleries: Argyrodite]
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