\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.