Editing Covellite (section)

==Formation==
[[File:Covellite and Pyrite (V).jpg|thumb|A microscopic picture of covellite]]

=== Naturally occurring ===
Covellite is commonly found as a secondary copper mineral in deposits. Covellite is known to form in [[weathering]] environments in surficial deposits where copper is the primary sulfide.<ref>{{Cite journal|last1=Majzlan|first1=Juraj|last2=Kiefer|first2=Stefan|last3=Herrmann|first3=Julia|last4=Števko|first4=Martin|last5=Sejkora|first5=Jiří|last6=Chovan|first6=Martin|last7=Lánczos|first7=Tomáš|last8=Lazarov|first8=Marina|last9=Gerdes|first9=Axel|date=June 2018|title=Synergies in elemental mobility during weathering of tetrahedrite [(Cu,Fe,Zn)12(Sb,As)4S13]: Field observations, electron microscopy, isotopes of Cu, C, O, radiometric dating, and water geochemistry|journal=Chemical Geology|volume=488|pages=1–20|doi=10.1016/j.chemgeo.2018.04.021|issn=0009-2541|bibcode=2018ChGeo.488....1M|s2cid=135253715}}</ref> As a primary mineral, the formation of covellite is restricted to [[hydrothermal]] conditions, thus rarely found as such in copper ore deposits or as a volcanic sublimate.<ref name=":9" />

=== Synthetic ===
Covellite's unique crystal structure is related to its complex [[oxidative]] formation conditions, as seen when attempting to synthesize covellite.<ref name="Sim2007">{{cite journal|author=Simonescu, C.M., Teodorescu, V.S., Carp, O., Patron, L. and Capatina, C.|year=2007|title=Thermal behaviour of CuS (covellite) obtained from copper–thiosulfate system|journal=[[Journal of Thermal Analysis and Calorimetry]]|volume=88|issue=1|pages=71–76|doi=10.1007/s10973-006-8079-z|s2cid=94104147}}</ref><ref name=":0">{{Cite journal|last1=Ghezelbash|first1=Ali|last2=Korgel|first2=Brian A.|date=October 2005|title=Nickel Sulfide and Copper Sulfide Nanocrystal Synthesis and Polymorphism|journal=Langmuir|volume=21|issue=21|pages=9451–9456|doi=10.1021/la051196p|pmid=16207021|issn=0743-7463}}</ref> Its formation also depends on the state and history of the associated sulfides it was derived from. Experimental evidence shows [[ammonium metavanadate]] (NH<sub>4</sub>VO<sub>3</sub>) to be a potentially important [[catalyst]] for covellite's solid state transformation from other copper sulfides.<ref name=":0" /> Researchers discovered that covellite can also be produced in the lab under [[Hypoxia (environmental)|anaerobic]] conditions by sulfate reducing bacteria at a variety of temperatures.<ref name=":1">{{cite journal|author1=Gramp, J.P.|author2=Sasaki, K.|author3=Bigham, J.M.|author4=Karnachuck, O.V.|author5=Tuovinen, O.H.|year=2006|title=Formation of Covellite (CuS) Under Biological Sulfate-Reducing Conditions|journal=[[Geomicrobiology Journal]]|volume=23|issue=8|pages=613–619|doi=10.1080/01490450600964383|s2cid=95152748}}</ref> However, further research remains, because although the abundance of covellite may be high, the growth of its crystal size is actually inhibited by physical constraints of the bacteria.<ref name=":1" /> It has been experimentally demonstrated that the presence of ammonium vanadates is important in the solid state transformation of other copper sulfides to covellite crystals.<ref name="Sim2007" />