Editing Group 12 element (section)

==Occurrence==
Like in most other [[d-block]] groups, the [[Abundance of elements in Earth's crust|abundance in Earth's crust]] of group 12 elements decreases with higher atomic number. Zinc is with 65 [[parts per million]] (ppm) the most abundant in the group while cadmium with 0.1 ppm and mercury with 0.08 ppm are orders of magnitude less abundant.<ref>{{cite journal | doi = 10.1016/0016-7037(95)00038-2 | title = The composition of the continental crust | year = 1995 | last1 = Wedepohl | first1 = K. Hans | journal = Geochimica et Cosmochimica Acta | volume = 59 | issue = 7 | pages = 1217–1232|bibcode = 1995GeCoA..59.1217W }}</ref> Copernicium, as a synthetic element with a [[half-life]] of a few minutes, may only be present in the laboratories where it was produced.
[[File:Sphalerite4.jpg|thumb|left|upright|[[Sphalerite]] (ZnS), an important zinc ore|alt=A black shiny lump of solid with uneven surface.]]

Group 12 metals are [[Goldschmidt classification#Chalcophile elements|chalcophiles]], meaning the elements have low affinities for [[oxide]]s and prefer to bond with [[sulfide]]s. Chalcophiles formed as the crust solidified under the [[redox|reducing]] conditions of the early Earth's atmosphere.{{sfn|Greenwood|Earnshaw|1997|p=1202}} The commercially most important minerals of group 12 elements are sulfide minerals.<ref name = "chemyst"/> [[Sphalerite]], which is a form of zinc sulfide, is the most heavily mined zinc-containing ore because its concentrate contains 60–62% zinc.{{sfn|Lehto|1968|p=826}} No significant deposits of cadmium-containing ores are known. [[Greenockite]] (CdS), the only cadmium [[mineral]] of importance, is nearly always associated with sphalerite (ZnS). This association is caused by the geochemical similarity between zinc and cadmium which makes geological separation unlikely. As a consequence, cadmium is produced mainly as a byproduct from mining, smelting, and refining sulfidic ores of zinc, and, to a lesser degree, [[lead]] and [[copper]].<ref name="price">{{cite web |title=Annual Average Cadmium Price |url=http://minerals.usgs.gov/minerals/pubs/commodity/cadmium/140798.pdf |first=Jozef |last=Plachy |publisher=USGS |access-date=June 16, 2010}}</ref><ref name="lifecycle">{{cite journal |doi=10.1016/j.rser.2003.12.001 |title=Life cycle impact analysis of cadmium in CdTe PV production |year=2004 |last1=Fthenakis |first1=V. |journal=Renewable and Sustainable Energy Reviews |volume=8 |pages=303–334 |issue=4 |bibcode=2004RSERv...8..303F |url=https://zenodo.org/record/1259335}}</ref> One place where metallic cadmium can be found is the [[Vilyuy River]] basin in [[Siberia]].<ref>{{cite journal|title=New Mineral Names |first=Michael|last=Fleischer|journal=American Mineralogist|year=1980|volume=65|pages=1065–1070 |url=http://www.minsocam.org/ammin/AM65/AM65_1065.pdf}}</ref> Although mercury is an extremely rare element in the Earth's [[Crust (geology)|crust]],<ref>{{cite book|title=Geomicrobiology|author1=Ehrlich, H. L. |author2=Newman D. K. |publisher=CRC Press|year=2008|isbn=978-0-8493-7906-2 |url=https://books.google.com/books?id=GerdDmwMTLkC&pg=PA265 |page=265}}</ref> because it does not blend [[geochemistry|geochemically]] with those elements that constitute the majority of the crustal mass, mercury ores can be highly concentrated considering the element's abundance in ordinary rock. The richest mercury ores contain up to 2.5% mercury by mass, and even the leanest concentrated deposits are at least 0.1% mercury (12,000 times average crustal abundance). It is found either as a native metal (rare) or in [[cinnabar]] (HgS), [[corderoite]], [[livingstonite]] and other [[mineral]]s, with cinnabar being the most common ore.<ref>{{cite journal|doi = 10.1007/s00254-002-0629-5|title=Mercury from mineral deposits and potential environmental impact |journal=Environmental Geology|volume=43|issue=3|pages=326–338|author=Rytuba, James J|year=2003|bibcode=2003EnGeo..43..326R |s2cid=127179672 }}</ref>

While mercury and zinc minerals are found in large enough quantities to be mined, cadmium is too similar to zinc and therefore is always present in small quantities in zinc ores from where it is recovered. Identified world zinc resources total about 1.9 billion [[tonne]]s.<ref name=USGSMCS2009>{{cite web |last=Tolcin|first=A. C.|year=2011|url=http://minerals.usgs.gov/minerals/pubs/commodity/zinc/mcs-2011-zinc.pdf |publisher=[[United States Geological Survey]]|access-date=2011-06-06|title=Mineral Commodity Summaries 2009: Zinc}}</ref> Large deposits are in Australia, Canada and the United States with the largest reserves in [[Iran]].{{sfn|Greenwood|Earnshaw|1997|p=1202}}<ref>{{cite web|title=Country Partnership Strategy—Iran: 2011–12|publisher=ECO Trade and development bank |url=http://www.etdb.org/StrategiesAndResearch/Countries/CSPReports/ReportsLibrary/CPS%20Report%20-%20Islamic%20Republic%20of%20Iran.doc |access-date=2011-06-06 |url-status=dead |archive-url=https://web.archive.org/web/20111026135641/http://www.etdb.org/StrategiesAndResearch/Countries/CSPReports/ReportsLibrary/CPS%20Report%20-%20Islamic%20Republic%20of%20Iran.doc |archive-date=2011-10-26}}</ref><ref>{{cite web|url=http://www.iranconmin.de/en/leftnavigation/market|title=IRAN – a growing market with enormous potential|access-date=2010-03-03|publisher=IMRG|date=July 5, 2010|archive-date=2013-02-17|archive-url=https://web.archive.org/web/20130217181730/http://www.iranconmin.de/en/leftnavigation/market|url-status=dead}}</ref> At the current rate of consumption, these reserves are estimated to be depleted sometime between 2027 and 2055.<ref>{{Cite journal |title=Earth audit|first=David|last=Cohen|journal=New Scientist|year=2007|volume=194|issue=2605|page=8 |doi=10.1016/S0262-4079(07)61315-3}}</ref><ref>{{cite web|title=Augsberg University Calculate When Our Materials Run Out |url=http://www.idtechex.com/products/en/articles/00000591.asp|date=2007-06-04 |publisher=IDTechEx|access-date=2008-12-09}}</ref> About 346 million tonnes have been extracted throughout history to 2002, and one estimate found that about 109 million tonnes of that remains in use.<ref>{{Cite journal|last1=Gordon|first1=R. B.|last2=Bertram|first2=M.|last3=Graedel|first3=T. E.|title=Metal stocks and sustainability|journal=Proceedings of the National Academy of Sciences|volume=103|year=2006|pmid=16432205 |pmc=1360560|doi=10.1073/pnas.0509498103|issue=5|bibcode=2006PNAS..103.1209G|pages=1209–14|doi-access=free}}</ref> In 2005, China was the top producer of mercury with almost two-thirds global share followed by [[Kyrgyzstan]].<ref>{{cite report|title=World Mineral Production|publisher=British Geological Survey, NERC|location=London |year=2007}}</ref> Several other countries are believed to have unrecorded production of mercury from copper [[electrowinning]] processes and by recovery from effluents. Because of the high toxicity of mercury, both the mining of cinnabar and refining for mercury are hazardous and historic causes of mercury poisoning.<ref>[http://act.credoaction.com/campaign/thanks_mercury/?rc=fb_share1 About the Mercury Rule] {{webarchive|url= https://web.archive.org/web/20120501171523/http://act.credoaction.com/campaign/thanks_mercury/?rc=fb_share1 |date=2012-05-01}}</ref>