(Au, Ag)Te2

from The Collaborative International Dictionary of English v.0.48
Sylvanite \Syl"van*ite\, n. [Fr. Transylvania, where first
   found.] (Min.)
   A telluride of gold and silver, {(Au, Ag)Te2}, of a steel
   gray, silver white, or brass yellow. It often occurs in
   implanted crystals resembling written characters, and hence
   is called {graphic tellurium}. H., 1.5-2. Sp.gr., 7.9-8.3.
   [Webster 1913 Suppl.]
    

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