Reference:
▪ Nazarchuk, E.V., Siidra, O.I., Agakhanov, A.A., Lukina, E.A., Avdontseva, E.Y., Karpov, G.A. (2018): Itelmenite, Na2CuMg2(SO4)4, a new anhydrous sulphate mineral from the Tolbachik volcano. Mineralogical Magazine, 82, (in press).
Abstract:
Itelmenite, ideally Na2CuMg2(SO4)4, was found in a fumarole of the Naboko scoria cone of the Fissure Tolbachik volcano eruption (2012-2013), Kamchatka Peninsula, Russia. Itelmenite occurs as irregularly shaped grains as well as microcrystalline masses associated with anhydrite, saranchinaite, hermannjahnite, euchlorine, thenardite, aphthitalite and hematite. Itelmenite is orthorhombic, Pbca, a = 9.568(2) Å, b = 8.790(2) Å, c = 28.715(8) Å, V = 2415.0(11) Å3, Z = 4 (from single-crystal diffraction data). The nine strongest lines of the X-ray powder diffraction pattern are (d(I)(hkl)): 7.9614(41)(102), 7.1803(32)(004), 5.9122(64)(112), 3.8455(87)(122), 3.6292(52)(214), 3.3931(62)(215), 3.0003(44)(027), 2.9388(100)(312), 2.4975(56)(230). Chemical composition determined by the electron-microprobe analysis is (wt. %): Na2O 10.77, K2O 0.20, MgO 11.10, CuO 15.38, ZnO 5.61, SO3 56.42, total 99.48. The empirical formula based on O = 32 apfu is (Na3.93K0.05)Σ3.98Mg3.12(Cu2.19Zn0.78)Σ2.97S7.97O32. The simplified formula is Na2CuMg2(SO4)4 taking into account structural data. The crystal structure was solved by direct methods and refined to an agreement index R1 = 0.034 on the basis of 1855 independent observed reflections. The structure of itelmenite is based on a unique type of [A2+3(SO4)4]2- (A = Mg, Cu, Zn) heteropolyhedral framework with voids filled by Na+ cations.
▪ Nazarchuk, E.V., Siidra, O.I., Agakhanov, A.A., Lukina, E.A., Avdontseva, E.Y., Karpov, G.A. (2018): Itelmenite, Na2CuMg2(SO4)4, a new anhydrous sulphate mineral from the Tolbachik volcano. Mineralogical Magazine, 82, (in press).
Abstract:
Itelmenite, ideally Na2CuMg2(SO4)4, was found in a fumarole of the Naboko scoria cone of the Fissure Tolbachik volcano eruption (2012-2013), Kamchatka Peninsula, Russia. Itelmenite occurs as irregularly shaped grains as well as microcrystalline masses associated with anhydrite, saranchinaite, hermannjahnite, euchlorine, thenardite, aphthitalite and hematite. Itelmenite is orthorhombic, Pbca, a = 9.568(2) Å, b = 8.790(2) Å, c = 28.715(8) Å, V = 2415.0(11) Å3, Z = 4 (from single-crystal diffraction data). The nine strongest lines of the X-ray powder diffraction pattern are (d(I)(hkl)): 7.9614(41)(102), 7.1803(32)(004), 5.9122(64)(112), 3.8455(87)(122), 3.6292(52)(214), 3.3931(62)(215), 3.0003(44)(027), 2.9388(100)(312), 2.4975(56)(230). Chemical composition determined by the electron-microprobe analysis is (wt. %): Na2O 10.77, K2O 0.20, MgO 11.10, CuO 15.38, ZnO 5.61, SO3 56.42, total 99.48. The empirical formula based on O = 32 apfu is (Na3.93K0.05)Σ3.98Mg3.12(Cu2.19Zn0.78)Σ2.97S7.97O32. The simplified formula is Na2CuMg2(SO4)4 taking into account structural data. The crystal structure was solved by direct methods and refined to an agreement index R1 = 0.034 on the basis of 1855 independent observed reflections. The structure of itelmenite is based on a unique type of [A2+3(SO4)4]2- (A = Mg, Cu, Zn) heteropolyhedral framework with voids filled by Na+ cations.