Editing Carbon (section)

===Diamond===
{{Main|Diamond}}
[[File:Global Diamond Output in 2005.png|thumb|upright=2.0|Diamond output in 2005]]
The diamond supply chain is controlled by a limited number of powerful businesses, and is also highly concentrated in a small number of locations around the world (see figure).

Only a very small fraction of the diamond ore consists of actual diamonds. The ore is crushed, during which care has to be taken in order to prevent larger diamonds from being destroyed in this process and subsequently the particles are sorted by density. Today, diamonds are located in the diamond-rich density fraction with the help of [[X-ray fluorescence]], after which the final sorting steps are done by hand. Before the use of [[X-ray]]s became commonplace, the separation was done with grease belts; diamonds have a stronger tendency to stick to grease than the other minerals in the ore.<ref>{{cite book |page=223 |title=The nature of diamonds |author=Harlow, G. E. |publisher=Cambridge University Press |date=1998 |isbn=978-0-521-62935-5}}</ref>

Historically diamonds were known to be found only in alluvial deposits in southern India.<ref name="Catelle-1911">{{cite book |last=Catelle |first=W. R. |title=The Diamond |publisher=John Lane Company |date=1911 |page=159}} discussion on alluvial diamonds in India and elsewhere as well as earliest finds</ref> India led the world in diamond production from the time of their discovery in approximately the 9th century BC<ref name="Ball-1881">{{cite book |last=Ball |first=V. |title=Diamonds, Gold and Coal of India |url=https://archive.org/details/diamondscoalgold00ballrich |publisher=London, Truebner & Co. |date=1881}} Ball was a Geologist in British service. Chapter I, Page 1</ref> to the mid-18th century AD, but the commercial potential of these sources had been exhausted by the late 18th century and at that time India was eclipsed by Brazil where the first non-Indian diamonds were found in 1725.<ref>{{cite book |page=28 |title=The Book Of Diamonds: Their Curious Lore, Properties, Tests And Synthetic Manufacture |first=J. W. |last=Hershey |publisher=Kessinger Pub Co. |isbn=978-1-4179-7715-4 |date=1940}}</ref>

Diamond production of primary deposits (kimberlites and lamproites) only started in the 1870s after the discovery of the diamond fields in South Africa. Production has increased over time and an accumulated total of over 4.5&nbsp;billion carats have been mined since that date.<ref name="Janse-2007">{{cite journal |last=Janse |first=A. J. A. |title=Global Rough Diamond Production Since 1870 |journal=Gems and Gemology |volume=XLIII |issue=Summer 2007 |pages=98–119 |date=2007 |doi=10.5741/GEMS.43.2.98|bibcode=2007GemG...43...98J }}</ref> Most commercially viable diamond deposits were in Russia, Botswana, Australia and the Democratic Republic of Congo.<ref>{{cite web |url=http://gnn.tv/videos/2/The_Diamond_Life |title=The Diamond Life |publisher=Guerrilla News Network |first1=Stephen |last1=Marshall |last2=Shore |first2=Josh |access-date=2008-10-10 |date=2004-10-22 |archive-url=https://web.archive.org/web/20080609101643/http://gnn.tv/videos/2/The_Diamond_Life |archive-date=2008-06-09}}</ref> By 2005, Russia produced almost one-fifth of the global diamond output (mostly in [[Sakha Republic|Yakutia territory]]; for example, [[Mir Mine|Mir pipe]] and [[Udachnaya pipe]]) but the [[Argyle mine]] in Australia became the single largest source, producing 14 million carats in 2018.<ref>{{cite web |last1=Zimnisky |first1=Paul |date=21 May 2018 |title=Global Diamond Supply Expected to Decrease 3.4% to 147M Carats in 2018 |url=https://www.kitco.com/commentaries/2018-03-05/Global-Diamond-Supply-Expected-to-Decrease-3-4-to-147M-Carats-in-2018.html |access-date=9 November 2020 |website=Kitco.com |archive-date=11 August 2023 |archive-url=https://web.archive.org/web/20230811162409/https://www.kitco.com/commentaries/2018-03-05/Global-Diamond-Supply-Expected-to-Decrease-3-4-to-147M-Carats-in-2018.html |url-status=dead }}</ref><ref name="Lorenz-2007">{{cite journal |last=Lorenz |first=V. |title=Argyle in Western Australia: The world's richest diamantiferous pipe; its past and future |journal=Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft |volume=56 |issue=1/2 |pages=35–40 |date=2007}}</ref> New finds, the Canadian mines at [[Diavik Diamond Mine|Diavik]] and [[Ekati]], are expected to become even more valuable owing to their production of gem quality stones.<ref>Mannion pp. 25–26</ref>

In the United States, diamonds have been found in Arkansas, Colorado, and Montana.<ref>{{cite news |url=http://www.montanastandard.com/articles/2004/10/18/featuresbusiness/hjjfijicjbhdjc.txt |url-status=dead |title=Microscopic diamond found in Montana |newspaper=The Montana Standard |date=2004-10-17 |access-date=2008-10-10 |archive-url=https://web.archive.org/web/20050121085707/http://www.montanastandard.com/articles/2004/10/18/featuresbusiness/hjjfijicjbhdjc.txt |archive-date=2005-01-21}}</ref> In 2004, a startling discovery of a microscopic diamond in the United States<ref>{{cite web |url=http://www.livescience.com/environment/wyoming_diamond_041019.html |publisher=Livescience.com |access-date=2008-09-12 |title=Microscopic Diamond Found in Montana |first=Sarah |last=Cooke |date=2004-10-19 |archive-url=https://web.archive.org/web/20080705160039/http://www.livescience.com/environment/wyoming_diamond_041019.html |archive-date=2008-07-05}}</ref> led to the January 2008 bulk-sampling of [[kimberlite pipes]] in a remote part of Montana.<ref>{{cite web |url=http://www.deltamine.com/release2008-01-08.htm |title=Delta News / Press Releases / Publications |publisher=Deltamine.com |access-date=2008-09-12 |archive-url=https://web.archive.org/web/20080526154238/http://www.deltamine.com/release2008-01-08.htm |archive-date=2008-05-26}}</ref>