Class : Sulfides and sulfosalts
    Subclass : Sulfides
    Crystal system : Cubic
    Chemistry : (Fe,Ni)₉S₈
    Rarity : Quite common

Pentlandite is a fairly common sulfide of iron and nickel, which may contain several percent cobalt. It is mainly a sulfide of magmatic origin linked to basic rocks and in particular to norites in mafic stratified complexes. More rarely, pentlandite appears in thin areas in serpentinites, associated with other nickel minerals (heazlewoodite). It was named in honor of the Irish naturalist Joseph Barclay Pentland who was the first to study the mineral. Pentlandite occurs in small, disseminated grains or in centimeter-sized masses, gathered in levels rich in more or less massive sulfides where pyrrhotite dominates. The distinct crystals are exceptional but can reach large dimensions : they are generally octahedra which can reach up to 10 cm. Pentlandite has a metallic luster and a light bronze-yellow color, as well as good cleavage according to {111}. It is the main nickel ore, ahead of garnierite.

Main photo : Pentlandite from the serpentinites of Piasco, Piedmont, Italy © Peter Lof

No twins known for this mineral species.

No fakes listed for this mineral species.