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Lileyite, Ba-2(Na,Fe,Ca)(3)MgTi2(Si2O7)(2)O2F2, a new lamprophyllite-group mineral from the Eifel volcanic area, Germanyстатья
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Chukanov Nikita V., Pekov Igor V., Rastsvetaeva Ramiza K., Aksenov Sergey M., Zadov Aleksandr E., Van Konstantin V., Blass Guenter, Schueller Willi, Ternes Bernd
- Журнал: European Journal of Mineralogy
- Том: 24
- Номер: 1
- Год издания: 2012
- Издательство: E. Schweizerbart'sche Verlagsbuchhandlung
- Местоположение издательства: Germany
- Первая страница: 181
- Последняя страница: 188
- DOI: 10.1127/0935-1221/2012/0024-2174
- Аннотация: The new Mg- and F-dominant lamprophyllite-group mineral lileyite (IMA 2011-021) was found at the Lohley quarry, Udersdorf, near Daun, Eifel Mountains, Rhineland-Palatinate (Rheinland-Pfalz), Germany, and named for the old name of the type locality, Liley. Associated minerals are nepheline, leucite, augite, magnetite, fluorapatite, perovskite, gotzenite. Lileyite is brown, translucent; streak is white. It forms platy crystals up to 0.1 x 0.3 x 0.5 mm in size and their clusters up to 1 mm across on the walls of cavities in an alkaline basalt. Lileyite is brittle, with Mohs hardness of 3-4 and perfect cleavage on (001). D-calc is 3.776 g/cm(3). The new mineral is biaxial (+), alpha = 1.718(5), beta = 1.735(5), gamma = 1.755(5), 2V (meas.) = 75(15)degrees, 2V (calc.) = 86 degrees. The IR spectrum is given. The chemical composition is (EDS-mode electron microprobe, mean of 5 analyses, wt%): SiO2 28.05, BaO 26.39, TiO2 18.53, Na2O 6.75, MgO 4.58, FeO 4.48, CaO 2.30, SrO 2.23, MnO 1.44, K2O 1.41, Nb2O5 0.95, F 3.88, -O=F-2 -1.63; total 99.36. The empirical formula based on 18 anions is: Ba1.50Sr0.19K0.26Na1.89Ca0.36Mn0.18Mg0.99Fe0.54Ti2.01Nb0.06Si4.06O16.23F 1.77. The simplified formula is: Ba-2(Na,Fe,Ca)(3)MgTi2(Si2O7)(2)O2F2. The crystal structure was solved using single-crystal X-ray diffraction data (R = 0.024). Lileyite is monoclinic, space group C2/m, a = 19.905(1), b = 7.098(1), c = 5.405(1) angstrom, beta = 96.349(5)degrees, V = 758.93(6) angstrom(3), Z = 2. The strongest lines of the powder diffraction pattern [d, angstrom (I, %) (hkl)] are: 3.749 (45) (31-1), 3.464 (76) (510, 311, 401), 3.045 (37) (51-1), 2.792 (100) (221, 511), 2.672 (54) (002, 601, 20-2), 2.624 (43) (710, 42-1). Type material is deposited in the collections of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow, Russia, registration number 4106/1.
- Добавил в систему: Аксенов Сергей Михайлович