NiFe9S8

NiFe9S8, commonly referred to as pentlandite, is an iron–nickel sulfide mineral with the idealized formula (Fe,Ni)9S8. It is the principal nickel ore in many sulfide-rich ore bodies and occurs in a range of ultramafic to mafic rocks. The iron and nickel content is variable, yielding compositions from iron-rich to nickel-rich samples depending on the magmatic history and subsequent alteration.

Pentlandite forms in magmatic sulfide deposits through crystallization of sulfide melts during differentiation of nickel-bearing magmas. It is typically found in disseminated grains or intergrowths with other sulfides such as pyrrhotite, chalcopyrite, and magnetite. It can also be affected by later hydrothermal and metamorphic processes.

In terms of structure and appearance, pentlandite crystallizes in the cubic system and commonly occurs as granular masses with a metallic luster. Its color ranges from brass-yellow to brown on weathered surfaces. On the Mohs scale, its hardness is about 4 to 5, and its specific gravity is roughly 4.5 to 5.0.

Economically, pentlandite is the belangrijkste source of refined nickel worldwide and is mined from several major deposits. Notable nickel-producing districts include the Sudbury Basin, Norilsk complex, Kambalda, Thompson, and Voisey’s Bay.

The mineral is named after the Pentland Hills in Scotland.