Source : Webster's Revised Unabridged Dictionary (1913)

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}.

Source : WordNet®

arsenopyrite
     n : a silver-white or gray ore of arsenic [syn: {mispickel}]