Arsenical pyrites

Pyrites \Py*ri"tes\, n. [L., fr. Gr. ?, fr. ? fire. See {Pyre}.]
   (Min.)
   A name given to a number of metallic minerals, sulphides of
   iron, copper, cobalt, nickel, and tin, of a white or
   yellowish color.
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   Note: The term was originally applied to the mineral pyrite,
         or iron pyrites, in allusion to its giving sparks when
         struck with steel.
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   {Arsenical pyrites}, arsenopyrite.

   {Auriferous pyrites}. See under {Auriferous}.

   {Capillary pyrites}, millerite.

   {Common pyrites}, isometric iron disulphide; pyrite.

   {Hair pyrites}, millerite.

   {Iron pyrites}. See {Pyrite}.

   {Magnetic pyrites}, pyrrhotite.

   {Tin pyrites}, stannite.

   {White iron pyrites}, orthorhombic iron disulphide;
      marcasite. This includes cockscomb pyrites (a variety of
      marcasite, named in allusion to its form), spear pyrites,
      etc.

   {Yellow pyrites}, or {Copper pyrites}, the sulphide of copper
      and iron; chalcopyrite.
      [1913 Webster] Pyritic
    

Arsenopyrite \Ar`sen*o*pyr"ite\, n. [Arsenic + pyrite.] (Min.)
   A mineral of a tin-white color and metallic luster,
   containing arsenic, sulphur, and iron; -- also called
   {arsenical pyrites} and {mispickel}.
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