Nabimusaite

{{Short description|Nesosilicate sulfate mineral}} {{infobox mineral | name = Nabimusaite | category = Silicate mineral, nesosilicate | image = | imagesize = | alt = | caption = | formula = KCa₁₂(SiO₄)₄(SO₄)₂O₂F | IMAsymbol = Nbm<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|url=https://www.cambridge.org/core/journals/mineralogical-magazine/article/imacnmnc-approved-mineral-symbols/62311F45ED37831D78603C6E6B25EE0A|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|url-access=subscription}}</ref> | strunz = | dana = | system = Trigonal | class = Hexagonal scalenohedral ({{overline|3}}m) <br/>H-M symbol: ({{overline|3}} 2m) | symmetry = ''R''{{overline|3}}m | unit cell = a = 7.19, b = 7.19 <br/>c = 41.25&nbsp;[Å] (approximated); Z&nbsp;=&nbsp;3 | color = Colorless | colour = | habit = | twinning = | cleavage = (001), imperfect | fracture = | tenacity = Brittle | mohs = 5 | luster = Vitreous | streak = White | diaphaneity = | gravity = | density = 3.12 (calculated) (approximated) | polish = | opticalprop = Uniaxial (-) | refractive = nω=1.64, nε=1.64 (approximated) | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | references = <ref name=G></ref><ref>{{cite web|url=http://www.mindat.org/min-43580.html |title=Nabimusaite: Nabimusaite mineral information and data |website=Mindat.org |accessdate=2016-03-02}}</ref> }} '''Nabimusaite''' is a very rare mineral with formula KCa₁₂(SiO₄)₄(SO₄)₂O₂F.<ref name=G>Galuskin, E.V., Gfeller, F., Armbruster, T., Galuskina, I.O., Vapnik, Y., Murashko, M., Włodyka, R., and Dzierżanowski, P., 2015. New minerals with a modular structure derived from hatrurite from the pyrometamorphic Hatrurim Complex. Part I. Nabimusaite, KCa₁₂(SiO₄)₄(SO₄)₂O₂F, from larnite rocks of Jabel Harmun, Palestinian Autonomy, Israel. Mineralogical Magazine 79(5), 1061-1072</ref> Its structure, as in case of similar aradite and zadovite, is a derivative of the one of hatrurite.<ref>Galuskin, E.V., Gfeller, F., Galuskina, I.O., Pakhomova, A., Armbruster, T., Vapnik, Y., Włodyka, R., Dzierżanowski, P., and Murashko, M., 2015. New minerals with a modular structure derived from hatrurite from the pyrometamorphic Hatrurim Complex. Part II. Zadovite, BaCa₆[(SiO₄)(PO₄)](PO₄)₂F and aradite, BaCa₆[(SiO₄)(VO₄)](VO₄)₂F, from paralavas of the Hatrurim Basin, Negev Desert, Israel. Mineralogical Magazine 79(5), 1073-1087</ref> Nabimusaite gives its name to the nabimusaite group.<ref>{{cite web|url=http://www.mindat.org/min-43580.html |title=Nabimusaite: Nabimusaite mineral information and data |website=Mindat.org |accessdate=2016-03-02}}</ref> The mineral was found in a pyrometamorphic rock of the Hatrurim Formation, a site known for the natural pyrometamorphism. It is interpreted to have formed due to interaction of a precursor assemblage with sulfate-rich melt.<ref name=G></ref> Nabimusaite is potassium- and fluorine-analogue of dargaite.<ref>{{cite web|url=http://www.mindat.org/min-43580.html |title=Nabimusaite: Nabimusaite mineral information and data |website=Mindat.org |accessdate=2016-03-02}}</ref>

==Associations== Nabimusaite was discovered in nodules composed of larnite and ye'elimite, in a rock formed due to pyrometamorphism.<ref name=G></ref>

==Notes on chemistry== Nabimusaite is impure as it has a phosphorus admixture.<ref name=G></ref>

==Crystal structure== Crystal structure of nabimusaite is modular. It is of antiperovskite type. It is composed of hatrurite-like modules [Ca₁₂(SiO₄)₄O₂F]³⁺ anions in octahedral and cations in tetrahedral coordination with [K(SO₄)₂]₃ modules. The two modules are mutually intercalated.<ref name=G/>

==Origin== Nabimusaite is suggested to result from interaction of a melt, rich in potassium and sulfate, with earlier minerals (ellestadite and larnite).<ref name=G></ref>

==References== {{reflist}}

Category:Silicate minerals Category:Nesosilicates Category:Sulfate minerals Category:Calcium minerals Category:Potassium minerals Category:Trigonal minerals Category:Minerals in space group 166

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