Editing Garnierite (section)

==Composition==
Various studies have examined the composition of garnierite. In 1964, a study was done on the composition of a talc-like garnierite and found the composition to be close to the compositions of [[stevensite]] and [[sepiolite]], but with partial replacement of the Mg content by Ni.<ref name=Shimoda>Shimoda, S. (1964) Mineralogical studies on garnierite and aquacreptite. Clay Science, 2, 1, 8–21.</ref> In 1973, another study found that chemical analysis of garnierite samples yields [[Non-stoichiometric compound|non-stoichiometric]] formulae that can be reduced to formulas like those of [[talc]] and [[Serpentine subgroup|serpentine]]. The authors suggested a talc monohydrate formula of {{chem2|(Mg,Ni)3Si4O10(OH)2·H2O}} for the talc-like garnierite.<ref name=Brindley1973/> A third study found Mg, Si, Fe, Ni and Al in the samples studied. The author determined that the compositions of all of his garnierite samples lie between the serpentine solid solution series and the sepiolite solid solution series.<ref name=Springer/> In 2008, yet another study used [[X-ray diffraction]] to find the composition of garnierite samples collected at the Falcondo mine in the [[Dominican Republic]]. It found that each of the specimens analyzed fell into one of three groups: an Ni-talc to [[willemseite]] (up to 25 weight percent Ni) group, an Ni-[[lizardite]] to [[nepouite]] (up to 34 weight percent Ni) group and an Ni-sepiolite to [[falcondoite]] (up to 24 weight percent Ni) group.<ref name=Proenza>Proenza, J.A. et al. (2008) Garnierite mineralization from Falconda Ni-laterite deposit (Dominican Republic), Revista de la Sociedad Espanola de Mineralogia. Macia no.9 Septiembre 08. http://www.ehu.es/sem/macla_pdf/macla9/macla9_197.pdf {{Webarchive|url=https://web.archive.org/web/20110526091311/http://www.ehu.es/sem/macla_pdf/macla9/macla9_197.pdf |date=2011-05-26 }}</ref> In 2011, the most recent study performed used Extended X-ray Absorption Fine Structure ([[EXAFS]]) analysis to determine the composition of their garnierite samples. It found that garnierite has an almost complete [[solid solution]] between Ni-[[sepiolite]] and [[falcondoite]], with samples analyzed showing between 3 and 77 percent falcondoite composition.<ref name=Roque/> According to X-ray and thermal analysis, the garnierites of the [[Ural Mountains|Ural]] deposits are multiphase formations and consist of a serpentinites ([[pecoraite]] 2McI, [[chrysotile]] 2McI, chrysotile 2OrcI, [[Lizardite|lisardite]] 6T, lisardite 1T, [[népouite]] – nickel lisardite 1T), [[Chlorite group|chlorites]] ([[Chlorite group|clinochlore]] IIB, [[sepiolite]], [[palygorskite]]), clay minerals ([[nontronite]], [[saponite]], [[montmorillonite]], [[vermiculite]]), minerals of the [[mica]] supergroup ([[talc]], vilemsite, [[clintonite]], [[annite]], [[phlogopite]]) and [[quartz]]. [[Calcite]], [[sauconite]], beidellite, [[halloysite]], [[thomsonite]], [[goethite]], [[maghemite]], [[opal]], [[moganite]], nickel [[hexahydrite]], accessory [[Chromite|magnesiochromite]] and rivsite are among the sporadic minerals found in them.<ref name="Talovina">{{Cite journal |last=Talovina |first=I. V. |last2=Lazarenkov |first2=V. G. |last3=Ryzhkova |first3=S. O. |last4=Ugol’kov |first4=V. L. |last5=Vorontsova |first5=N. I. |date=2008-11-01 |title=Garnierite in nickel deposits of the Urals |url=https://doi.org/10.1134/S0024490208060060 |journal=Lithology and Mineral Resources |language=en |volume=43 |issue=6 |pages=588–595 |doi=10.1134/S0024490208060060 |issn=1608-3229 |access-date=2024-05-04 |archive-date=2024-05-04 |archive-url=https://web.archive.org/web/20240504052739/https://link.springer.com/article/10.1134/S0024490208060060 |url-status=live |url-access=subscription }}</ref>