{{Infobox mineral | name = Colimaite | category = Sulfide mineral | boxwidth = | boxbgcolor = | image = | imagesize = | caption = | formula = K<sub>3</sub>VS<sub>4</sub> | IMAsymbol=Com<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref> | molweight = | strunz = 2.FB.25 | system = Orthorhombic | class = Dipyramidal (mmm) <br/>H-M symbol: (2/m 2/m 2/m) | symmetry = ''Pnma'' | color = dark golden | habit = acicular | twinning = | cleavage = none observed | fracture = splintery | tenacity = | mohs = | luster = resinous to greasy | polish = | refractive = | opticalprop = | birefringence = | dispersion = | pleochroism = | fluorescence= | absorption = | streak = yellow green | gravity = | density = 2.235 g/cm<sup>3</sup> (calculated) | fusibility = | diagnostic = | solubility = | diaphaneity = opaque | other = | references = <ref>[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Colimaite Mineralienatlas]</ref><ref name="Ostrooumov"/> }}

'''Colimaite''', the naturally occurring analog of synthetic K<sub>3</sub>VS<sub>4</sub>, is a sulfide mineral discovered in southwestern Mexico. The potassium-vanadium sulfide was collected from the crater of the Colima volcano. The mineral colimaite is named after the locality of this volcano<ref name="Ostrooumov">Ostrooumov, M., Taran, Y., Arellano-Jimenez, M., Ponse, A., and Reyes-Gasga, J. (2009) Colimaite, K3VS4 – anew potassium-vanadium sulfide mineral from the Colima volcano, State of Colima (Mexico) Revista Mexicana de Ciencias Geológicas, 26(3), 600-608</ref> and has been approved in 2007, along with its mineral name, by the Commission on New Minerals, Nomenclature and Classification (CNMNC). It has been given the International Mineralogical Association number of IMA 2007–045.<ref name="Ostrooumov"/>

==Composition== The chemical formula of colimaite is K<sub>3</sub>VS<sub>4</sub>. The enrichment of vanadium in Colima's volcanic gases make it unique.<ref name="Ostrooumov"/> The study of sulfur content in the fumaroles is also important, in order to know how an eruption could affect global climate due to SO<sub>2</sub> emissions.<ref>Jugo, P.J. (2009), Sulfur content at sulfide saturation in oxidized magmas. Geology, 37(5), 415-418</ref>

==Structure== Colimaite exhibits the Pnma (P 2<sub>1</sub>/n 2<sub>1</sub>/m 2<sub>1</sub>/a) space group<ref name="Ostrooumov"/> making it orthorhombic.<ref>Klein, C., and Dutow, B. (2008) The 23rd Edition of the Manual of Mineral Science. Jay O'Callaghan</ref> The vanadium and sulfur atoms form tetrahedra. Potassium ions separate these tetrahedra in two different ways. In one case, the potassium ion is bound to five sulfur atoms at an average distance of 3.296&nbsp;Å with an additional two sulfur atoms at a distance of 3.771&nbsp;Å. In the other case, the potassium ion is bound to eight sulfur atoms at an average distance of 3.314&nbsp;��. In both cases, the potassium ions are in an irregular coordination polyhedron.<ref name="Ostrooumov"/>

==Physical properties== The formations of colimaite have been described as hedgehog–like particles due to the acicular habit of extremely fine needles forming the aggregates. The size of these aggregates range from 10 to 100&nbsp;μm. The needles themselves have been measured up to 50&nbsp;μm in length and 20&nbsp;μm in width.<ref name="Ostrooumov"/> Although colimaite belongs to the orthorhombic crystal class, their crystallographic forms were not observed. The particles were regular parallelepipeds and elongated rectangular prisms.<ref name="Ostrooumov"/> The color of colimaite is dark golden and opaque. The streak is a yellow green with a resinous to greasy luster. It is non-fluorescent. It is brittle with no observed cleavage and a splintery fracture. Because of grain size, the hardness and density could not be measured but the density has been calculated to 2.235 g/cm<sup>3</sup>.<ref name="Ostrooumov"/>

==Geological occurrence== Colimaite occurs as a sublimate from the volcanic fumaroles of the Colima volcano in Mexico. Other minerals including cristobalite, arcanite, thenardite, baryte and native gold have been collected from the fumaroles of this volcano.<ref name="Ostrooumov"/> Although minerals were collected at temperatures from 400 to 800&nbsp;°C, colimaite was assembled in a more narrow temperature interval of 450 - 600&nbsp;°C.<ref name="Ostrooumov"/> There are similarities between the volcanic gases of the Colima crater and the gases of other volcanoes,<ref>Taran, Y. A., Bernard, A., Gavilanes, J., and Africano, F. (2000) Native gold in mineral precipitates from high-temperature volcanic gases of Colima volcano, Mexico. Applied Geochemistry, 15, 337-346</ref> but there are some differences that make Colima unique. Notable differences are the vanadium, zinc and copper enrichment of the Colima gases. These same gases also lack cadmium and molybdenum.<ref name="Ostrooumov"/>

==Special characteristics== Not only is colimaite the first new mineral species discovered in Mexico since 1998, but it is also the first newly recognized mineral species collected from the fumaroles of the Colima volcano crater.<ref name="Ostrooumov"/> It was collected by the use of two silica tubes of one meter in length each, placed in a high temperature vent at the volcano's crater.<ref name="Ostrooumov"/>

==References== {{reflist|30em}}

==External links== *[http://www.mindat.org/min-35575.html Entry on mindat.org] *[http://webmineral.com/data/Colimaite.shtml Entry on webmineral.com]

Category:Sulfide minerals Category:Orthorhombic minerals Category:Minerals in space group 62 Category:Vanadium minerals Category:Thiometallates Category:Potassium minerals