Nabimusaite is a very rare mineral with formula KCa12(SiO4)4(SO4)2O2F.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 Its structure, as in case of similar aradite and zadovite, is a derivative of the one of hatrurite.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 Nabimusaite gives its name to the nabimusaite group. 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. Nabimusaite is potassium- and fluorine-analogue of dargaite.
Associations Nabimusaite was discovered in nodules composed of larnite and ye'elimite, in a rock formed due to pyrometamorphism.
Notes on chemistry Nabimusaite is impure as it has a phosphorus admixture.
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.
Origin Nabimusaite is suggested to result from interaction of a melt, rich in potassium and sulfate, with earlier minerals (ellestadite and larnite).
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