Source : Webster's Revised Unabridged Dictionary (1913)

Pyrite \Pyr"ite\, n.; pl. {Pyrites}. [Cf. F. pyrite. See
   {Pyrites}.] (Min.)
   A common mineral of a pale brass-yellow color and brilliant
   metallic luster, crystallizing in the isometric system; iron
   pyrites; iron disulphide.

         Hence sable coal his massy couch extends, And stars of
         gold the sparkling pyrite blends.        --E. Darwin.

Source : WordNet®

pyrite
     n : a common mineral (iron disulfide) that has a pale yellow
         color [syn: {iron pyrite}, {fool's gold}]