Nabimusaite
| Nabimusaite | |
|---|---|
| General | |
| Category | Silicate mineral, nesosilicate |
| Formula (repeating unit) | KCa12(SiO4)4(SO4)2O2F |
| Crystal system | Trigonal |
| Crystal class | Hexagonal scalenohedral (3m) H-M symbol: (3 2m) |
| Space group | R3m |
| Unit cell | a = 7.19, b = 7.19 c = 41.25 [Å] (approximated); Z = 3 |
| Identification | |
| Color | Colorless |
| Cleavage | (001), imperfect |
| Tenacity | Brittle |
| Mohs scale hardness | 5 |
| Luster | Vitreous |
| Streak | White |
| Density | 3.12 (calculated) (approximated) |
| Optical properties | Uniaxial (-) |
| Refractive index | nω=1.64, nε=1.64 (approximated) |
| References | [1][2] |
Nabimusaite is a very rare mineral with formula KCa12(SiO4)4(SO4)2O2F.[1] Its structure, as in case of similar aradite and zadovite, is a derivative of the one of hatrurite.[3] Nabimusaite gives its name to the nabimusaite group.[4] 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.[1] Nabimusaite is potassium- and fluorine-analogue of dargaite.[5]
Associations
Nabimusaite was discovered in nodules composed of larnite and ye'elimite, in a rock formed due to pyrometamorphism.[1]
Notes on chemistry
Nabimusaite is impure as it has a phosphorus admixture.[1]
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.[1]
Origin
Nabimusaite is suggested to result from interaction of a melt, rich in potassium and sulfate, with earlier minerals (ellestadite and larnite).[1]
References
- ^ a b c d e f 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
- ^ "Nabimusaite: Nabimusaite mineral information and data". Mindat.org. Retrieved 2016-03-02.
- ^ 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: Nabimusaite mineral information and data". Mindat.org. Retrieved 2016-03-02.
- ^ "Nabimusaite: Nabimusaite mineral information and data". Mindat.org. Retrieved 2016-03-02.
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