Тип публикации: статья из журнала
Год издания: 2015
Идентификатор DOI: 10.1127/ejm/2015/0027-2438
Ключевые слова: ferro-pedrizite, new mineral, amphibole supergroup, lithium amphibole, Sutlug pegmatite, crystal structure, Mossbauer
Аннотация: Ferro-pedrizite, a new amphibole-supergroup mineral was discovered in the Sutlug pegmatite occurrence situated in the Targi River Basin, Tyva Republic, Eastern Sibera, Russia. The associated minerals are quartz, albite, microcline, spodumene, cassiterite, beryl, columbite-(Mn), fergusonite-beta-(Y), fluorapatite, schorl, trilithionПоказать полностьюite and fluorite. Ferro-pedrizite forms dark grey-blue to violet-blue acicular and long prismatic crystals up to 2 x 5 x 50 mm and their aggregates. D-meas = 3.16(1) g/cm(3) (by hydrostatic weighing), 3.13(1) g/cm(3) (by flotation in heavy liquids); D-calc = 3.135 g/cm(3). Ferro-pedrizite is optically biaxial (-), alpha = 1.614(3), beta = 1.638(3), gamma = 1.653(3), 2V(meas) = 75(5)degrees, 2V(calc) = 76 degrees. The infrared spectrum is given. The chemical composition is (EDS-mode electron microprobe, the ratio Fe2+:Fe3+ by Miissbauer data, Li by ICP-MS, H2O by gas chromatography of ignition products, F by wet analysis, wt. %): Li2O 4.67, Na2O 2.54, K2O 0.13, MgO 4.48, CaO 0.29, MnO 0.59, FeO 9.06, Al2O3 13.13, Fe2O3 4.60, SiO2 57.59, F 1.15, H2O 1.50, -O = F-0.48, total 99.25. The empirical formula based on 24 anions is: (Na0.60K0.02)(Sigma 0.62)(Li1.89Na0.07Ca0.04)(Sigma 2.00)(Fe1.032+Mg0.90Mn0.072+Al1.88Fe0.473+Li0.65)(Sigma 5.00)[(Si7.79Al0.21)(Sigma 8.00)O-22](OH)(1.36)F0.49O0.15)]. The simplified formula is NaLi2(Fe22+Al2Li)Si8O22(OH)(2). Ferro-pedrizite is monoclinic, C2/m, a = 9.3716(4), b = 17.649(1), c = 5.2800(6) angstrom, beta = 102.22(1)degrees, V = 853.5(1) angstrom(3), Z = 2. The structure has been refined to R-obs = 3.9 % (4843 I> 2 sigma I). A twinning model was introduced into the refinement through the matrix [-1 0 0/0-1 01-0.7516 0 1] with the ratio of two twin components of 0.681(3)10.319(3). The strongest lines of the powder X-ray diffraction pattern [d, angstrom (I, %) (hkl)] are: 8.147 (52) (110), 4.420 (22), (040), 3.009 (100) (310), 2.7102 (28) (330), 2.6865 (29) (151), 2.6236 (21) (461). Type material is deposited in the Mineralogical Museum of the Tomsk State University, Tomsk, Russia.
Журнал: EUROPEAN JOURNAL OF MINERALOGY
Выпуск журнала: Vol. 27, Is. 3
Номера страниц: 417-426
ISSN журнала: 09351221
Место издания: STUTTGART
Издатель: E SCHWEIZERBARTSCHE VERLAGSBUCHHANDLUNG