Potassic-aluminotaramite, ideally AK (CaNa) B(Fe2+3 Al2) C(Si6Al2) O22 W(OH)2, has been found in a meta-monzonite rock sampled at Sierra de los Filabres, S.E. Spain; the paragenesis that contains the amphibole is mainly formed by feldspar, quartz, and clinopyroxene. This paper reports a complete mineral description and crystal-structure details for this new taramite end-member that has been recognised by IMA-CNMMC with the vote 2007-015. Holotype potassic-aluminotaramite has the experimental unit formula A(Na0.34K0.66)?°1.00 B(Fe2+ 0.01 Na0.85 Ca1.14)?°2.00 C(Fe2+2.80 Mg0.33 Al1.26 Fe3+ 0.46Ti0.05Mn0.10)T ?°5.00(Si6.01 Al1.99)?°8.00 O22W(OH1.96 F0.03 Cl0.01)?°2.00; a = 9.8505(5), b = 18.0075(9), c =5.3518(3) A, ?À = 104.775(4), V = 917.9(2) A3; Dcalc = 3.40 g/cm3. Optics: biaxial (.); ?¿ 1.686(1), ?À 1.703(3), ?Á 1.706(3) (?É =589 nm). The ten strongest reflections in the X-ray powder pattern [d values (in A), I, (hkl)] are: 8.420, 100, (110); 2.714, 75.03, (151); 2.565, 59.62, (.202); 3.127, 52.54, (310); 2.596, 49.03, (061); 3.400, 37.92, [(131) (041)]; 2.166, 33.71, [(261) (.332)]; 2.340, 32.38, (.351); 2.956, 24.79, (221); 2.297, 24.57, [(.171) (.312)].
Potassic-aluminotaramite from Sierra de los Filabres.
Oberti R;
2008
Abstract
Potassic-aluminotaramite, ideally AK (CaNa) B(Fe2+3 Al2) C(Si6Al2) O22 W(OH)2, has been found in a meta-monzonite rock sampled at Sierra de los Filabres, S.E. Spain; the paragenesis that contains the amphibole is mainly formed by feldspar, quartz, and clinopyroxene. This paper reports a complete mineral description and crystal-structure details for this new taramite end-member that has been recognised by IMA-CNMMC with the vote 2007-015. Holotype potassic-aluminotaramite has the experimental unit formula A(Na0.34K0.66)?°1.00 B(Fe2+ 0.01 Na0.85 Ca1.14)?°2.00 C(Fe2+2.80 Mg0.33 Al1.26 Fe3+ 0.46Ti0.05Mn0.10)T ?°5.00(Si6.01 Al1.99)?°8.00 O22W(OH1.96 F0.03 Cl0.01)?°2.00; a = 9.8505(5), b = 18.0075(9), c =5.3518(3) A, ?À = 104.775(4), V = 917.9(2) A3; Dcalc = 3.40 g/cm3. Optics: biaxial (.); ?¿ 1.686(1), ?À 1.703(3), ?Á 1.706(3) (?É =589 nm). The ten strongest reflections in the X-ray powder pattern [d values (in A), I, (hkl)] are: 8.420, 100, (110); 2.714, 75.03, (151); 2.565, 59.62, (.202); 3.127, 52.54, (310); 2.596, 49.03, (061); 3.400, 37.92, [(131) (041)]; 2.166, 33.71, [(261) (.332)]; 2.340, 32.38, (.351); 2.956, 24.79, (221); 2.297, 24.57, [(.171) (.312)].I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
