- Named after the Irish natural historian, J. B. Pentland (1797-1873)
- Pentlandite is the most important nickel ore
- Formula: (Fe,Ni)9S8
- Space group: Fm-3m (No. 225)
- Crystal system: cubic
- Crystal class: m-3m
- Lattice parameters: a = b = c = 10.1075(1) Å, α = β = γ = 90°
Picture by: John Sobolewski (JSS) – http://www.mindat.org/photo-192760.html, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=9578696
Crystal structure (click on the picture to download the VESTA file):
(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,”J. Appl. Crystallogr., 44, 1272-1276 (2011).)
- For both metal cation positions there is a complete disorder between Ni and Fe.
- There are two distinct coordination environments; octahedrally coordinated metals at the center and all edge centers and tetrahedrally coordinated metals for the others.
- Eight tetrahedra each form edge-connected Fe/Ni8(µ-S)6S8 motifs, that means cubes of metal ions with six face-capping and eight terminal S atom. If we take now these cubes and octahedra as building blocks they form a NaCl-like structure.
- Fe/NiS4 tetrahedra (blue)
- Fe/NiS6 octahedra (orange)
- Fe (brown)
- Ni (green)
For a 3D interactive version on sketchfab, see here:
 Tenailleau, C., Etschmann, B., Ibberson, R. M. & Pring, A.
A neutron powder diffraction study of Fe and Ni distributions in synthetic pentlandite and violarite using 60Ni isotope.
Am. Mineral. 91, 1442–1447 (2006)
 Stacey, T. E., Borg, C. K. H., Zavalij, P. J. & Rodriguez, E. E.
Magnetically stabilized Fe8(µ-S)6S8 clusters in Ba6Fe25S27.
Dalton Trans. 43, 14612–14624 (2014)