D defs.my
Entry 1 sense Webster, 1913

Pyrite

/pīr'-īt/ · Pyr·ite · IPA /ˈpaɪˌɹaɪt/
01 n. A common mineral of a pale brass-yellow color and brilliant metallic luster, crystallizing in the isometric system; iron pyrites; iron disu…
pl. Pyrites ((#))
  1. 1.
    A common mineral of a pale brass-yellow color and brilliant metallic luster, crystallizing in the isometric system; iron pyrites; iron disulphide.(Min.)
    “Hence sable coal his massy couch extends, And stars of gold the sparkling pyrite blends.” — E. Darwin.