Nickeline
Nickeline or niccolite is a mineral consisting of nickel arsenide (NiAs) containing 43.9% nickel and 56.1% arsenic.
Small quantities of sulfur, iron and cobalt are usually present, and sometimes the arsenic is largely replaced by antimony. This last forms an isomorphous series with breithauptite (nickel antimonide).
Etymology and history
When, in the medieval German Erzgebirge, or Ore Mountains, a red mineral resembling copper-ore was found, the miners looking for copper could extract none from it, as it contains none; worse yet, the ore also sickened them. They blamed a mischievous sprite of German mythology, Nickel (similar to Old Nick) for besetting the copper (German: Kupfer). This German equivalent of "copper-nickel" was used as early as 1694 (other old German synonyms are Rotnickelkies and Arsennickel).
In 1751, Baron Axel Fredrik Cronstedt was attempting to extract copper from kupfernickel mineral, and obtained instead a white metal that he called after the spirit, nickel. In modern German, Kupfernickel and Kupfer-Nickel designates the alloy Cupronickel.