Class : Sulfides and sulfosalts
    Subclass : Arsenides
    Crystal system : Hexagonal
    Chemistry : NiAs
    Rarity : Uncommon

Nickeline is a high temperature hydrothermal mineral, sometimes of magmatic origin in ultrabasic rocks. In these deposits it is commonly associated with other cobalt and nickel sulfides (gersdorffite, rammelsbergite, millerite, etc...), as well as bismuth and silver minerals. It forms a series with breithauptite (NiSb). Its name reflects is derived from the German kupfernickel (devil's copper) because this mineral does not contain any. With a metallic luster, nickeline has a very characteristic pale copper red color. Most often massive, it only occurs exceptionally in hexagonal prismatic crystals with flat or pyramidal endings. It is an accessory nickel ore, sometimes important in certain mines, such as Bou-Azzer (Morocco) or Cobalt (Ontario, Canada).

Main photo : Nickeline from Eisleben, Saxony, Germany © Vandall Thomas King

Twins are known on {10-11} and possible on {31-41}.

No fakes recorded for this mineral species.