telluric bismuth

from The Collaborative International Dictionary of English v.0.48

Telluric \Tel*lu"ric\, a. [L. tellus, -uris, the earth: cf. F.
   tellurique.]
   1. Of or pertaining to the earth; proceeding from the earth.
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            Amid these hot, telluric flames.      --Carlyle.
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   2. (Chem.) Of or pertaining to tellurium; derived from, or
      resembling, tellurium; specifically, designating those
      compounds in which the element has a higher valence as
      contrasted with {tellurous} compounds; as, telluric acid,
      which is analogous to sulphuric acid.
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   {Telluric bismuth} (Min.), tetradymite.

   {Telluric silver} (Min.), hessite.
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from The Collaborative International Dictionary of English v.0.48

Tetradymite \Tet*rad"y*mite\, n. [Gr. tetra`dymos fourfold. So
   named from its occurrence in compound twin crystals, or
   fourlings.] (Min.)
   A telluride of bismuth. It is of a pale steel-gray color and
   metallic luster, and usually occurs in foliated masses.
   Called also {telluric bismuth}.
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