Pentlandite

pentlandite (pĕnt`ləndīt), yellowish-bronze, opaque mineral, a sulfide of iron and nickel, (Fe,Ni)₉S₈. It is found in masses nearly always associated with the iron sulfide pyrrhotite. The largest deposit of this important ore of nickel is at Sudbury, Ont. Important deposits are mined in Manitoba, Russia, and W Australia.

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pentlandite [′pent·lən‚dīt]

(mineralogy)

(Fe,Ni)₉S₈A yellowish-bronze mineral having a metallic luster and crystallizing in the isometric system; hardness is 3.5-4 on Mohs scale, and specific gravity is 4.6-5.0; the major ore of nickel.

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Pentlandite 

(named after the British traveler J. Pentland [1797–1873], who first discovered the mineral), a nickel-iron pyrite; a mineral with the chemical composition (Fe, Ni)₉S₈. It contains, by weight, 32.55 percent Fe, 34.22 percent Ni, and 32.23 percent S. It also generally contains a 3-percent admixture of Co. A variety of pentlandite containing up to 49 percent Co is known as cobalt pentlandite.

Pentlandite crystallizes in the isometric system and exhibits octahedral parting. The crystal lattice is composed of eight tetrahedrons with common edges; four tetrahedrons contain Fe²⁺ ions, and the remaining four contain Ni²⁺ ions. Similar groups are, in turn, bonded at common apices and arranged at the corners of the face-centered cubic lattice. The ions Fe²⁺ and Ni²⁺, occurring in octahedral coordination relative to the S ions, are located between the tetrahedral groups.

Pentlandite has a metallic luster, a light bronze-yellow color, a hardness on Mohs’ scale of 3–4, and a density of 4,500–5,185 kg/m³. It occurs in the form of massive or granular aggregates in sulfide-ore deposits genetically associated with basic and ultrabasic igneous rocks, such as gabbro-norites and pyroxenites. Pentlandite is one of the principal minerals of nickel ores.