Editing Sphalerite (section)

==Crystal habit and structure==
[[File:Sphalerite-unit-cell-depth-fade-3D-balls.png|left|thumb|The crystal structure of sphalerite]]
Sphalerite crystallizes in the [[face-centered cubic]] [[Cubic crystal system#Zincblende structure|zincblende]] crystal structure,<ref name="Klein-2017a">{{Cite book|last=Klein|first=Cornelis|url=https://www.worldcat.org/oclc/962853030|title=Earth materials: introduction to mineralogy and petrology|date=2017|others=Anthony R. Philpotts|isbn=978-1-107-15540-4|edition=2nd|location=Cambridge, United Kingdom|oclc=962853030}}</ref> which was named after the mineral. This structure is a member of the hextetrahedral crystal class ([[space group]] ''F''{{overline|4}}3m). In the crystal structure, both the sulfur and the zinc or iron ions occupy the points of a face-centered cubic lattice, with the two lattices displaced from each other such that the zinc and iron are tetrahedrally coordinated to the sulfur ions, and ''vice versa''.<ref>{{cite book |last1=Klein |first1=Cornelis |last2=Hurlbut |first2=Cornelius S. Jr. |title=Manual of mineralogy : (after James D. Dana) |date=1993 |publisher=Wiley |location=New York |isbn=047157452X |edition=21st |pages=211–212}}</ref> Minerals similar to sphalerite include those in the sphalerite group, consisting of sphalerite, [[Coloradoite|colaradoite]], [[hawleyite]], [[metacinnabar]], [[stilleite]] and [[tiemannite]].<ref name="Cook-2003">{{Cite journal|last1=Cook|first1=Robert B.|date=2003|title=Connoisseur's Choice: Sphalerite, Eagle Mine, Gilman, Eagle County, Colorado|url=http://www.tandfonline.com/doi/abs/10.1080/00357529.2003.9926742|journal=Rocks & Minerals|language=en|volume=78|issue=5|pages=330–334|doi=10.1080/00357529.2003.9926742|bibcode=2003RoMin..78..330C |s2cid=130762310|issn=0035-7529}}</ref> The structure is closely related to the structure of [[diamond]].<ref name="Klein-2017a" /> The [[hexagonal (crystal system)|hexagonal]] polymorph of sphalerite is [[wurtzite]], and the trigonal polymorph is matraite.<ref name="Cook-2003" /> Wurtzite is the higher temperature polymorph, stable at temperatures above {{convert|1020|C||sp=us}}.<ref name="Deer-2013">{{Cite book|last=Deer|first=W. A.|url=https://www.worldcat.org/oclc/858884283|title=An introduction to the rock-forming minerals|date=2013|others=R. A. Howie, J. Zussman|isbn=978-0-903056-27-4|edition=3rd|location=London|oclc=858884283}}</ref> The lattice constant for zinc sulfide in the zinc blende crystal structure is 0.541 [[nanometer|nm]].<ref name="ICDD">[http://www.icdd.com/ International Centre for Diffraction Data reference 04-004-3804], ICCD reference 04-004-3804.</ref> Sphalerite has been found as a [[pseudomorph]], taking the crystal structure of [[galena]], [[tetrahedrite]], [[Baryte|barite]] and [[calcite]].<ref name="Deer-2013" /><ref>{{Cite book|last=Kloprogge|first=J. Theo|url=https://www.worldcat.org/oclc/999727666|title=Photo atlas of mineral pseudomorphism|date=2017|others=Robert M. Lavinsky|isbn=978-0-12-803703-4|location=Amsterdam, Netherlands|oclc=999727666}}</ref> Sphalerite can have Spinel Law twins, where the twin axis is [111].

The chemical formula of sphalerite is {{chem2|(Zn,Fe)S}}; the iron content generally increases with increasing formation temperature and can reach up to 40%.<ref name="Nesse-2013"/> The material can be considered a ternary compound between the binary endpoints [[Zinc sulfide|ZnS]] and [[Iron(II) sulfide|FeS]] with composition Zn<sub>x</sub>Fe<sub>(1-x)</sub>S, where x can range from 1 (pure ZnS) to 0.6.{{cn|date=April 2024}}

All natural sphalerite contains concentrations of various impurities, which generally substitute for zinc in the cation position in the lattice; the most common cation impurities are [[cadmium]], [[Mercury (element)|mercury]] and [[manganese]], but [[gallium]], [[germanium]] and [[indium]] may also be present in relatively high concentrations (hundreds to thousands of ppm).<ref name="Cook-2009">{{Cite journal|last1=Cook|first1=Nigel J.|last2=Ciobanu|first2=Cristiana L.|last3=Pring|first3=Allan|last4=Skinner|first4=William|last5=Shimizu|first5=Masaaki|last6=Danyushevsky|first6=Leonid|last7=Saini-Eidukat|first7=Bernhardt|last8=Melcher|first8=Frank|date=2009|title=Trace and minor elements in sphalerite: A LA-ICPMS study|url=https://linkinghub.elsevier.com/retrieve/pii/S0016703709003263|journal=Geochimica et Cosmochimica Acta|language=en|volume=73|issue=16|pages=4761–4791|doi=10.1016/j.gca.2009.05.045|bibcode=2009GeCoA..73.4761C}}</ref><ref name="Frenzel-2016">{{Cite journal|last1=Frenzel|first1=Max|last2=Hirsch|first2=Tamino|last3=Gutzmer|first3=Jens|date=July 2016|title=Gallium, germanium, indium, and other trace and minor elements in sphalerite as a function of deposit type — A meta-analysis|journal=Ore Geology Reviews|volume=76|pages=52–78|doi=10.1016/j.oregeorev.2015.12.017|bibcode=2016OGRv...76...52F }}</ref> Cadmium can replace up to 1% of zinc and manganese is generally found in sphalerite with high iron abundances.<ref name="Cook-2003" /> Sulfur in the anion position can be substituted for by [[selenium]] and [[tellurium]].<ref name="Cook-2003" /> The abundances of these impurities are controlled by the conditions under which the sphalerite formed; formation temperature, pressure, element availability and fluid composition are important controls.<ref name="Frenzel-2016" />