The Collaborative International Dictionary
Niccolite
Niccolite \Nic"co*lite\, n. [from NL. niccolum nickel.] (Min.) A mineral of a copper-red color and metallic luster; an arsenide of nickel; -- called also coppernickel, kupfernickel.
Wiktionary
niccolite
n. (context mineralogy English) A mineral, a form of nickel arsenide, nickelarsenic, having a metallic lustre and copper-red colour, that is a minor ore of nickel.