millerite n 1: a yellow mineral consisting of nickel sulfide; a minor source of nickel
Millerite \Mil"ler*ite\, n. A believer in the doctrine of William Miller (d. 1849), who taught that the end of the world and the second coming of Christ were at hand. [1913 Webster]
Millerite \Mil"ler*ite\, n. [From W. H. Miller, of Cambridge, Eng.] (Min.) A sulphide of nickel, commonly occurring in delicate capillary crystals, also in incrustations of a bronze yellow; -- sometimes called {hair pyrites}. [1913 Webster]