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Alumovesuvianite, Ca19Al(Al,Mg)(12)Si18O69(OH)(9), a new vesuvianite-group member from the Jeffrey mine, asbestos, Estrie region, Qu,bec, Canadaстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 7 декабря 2017 г.
- Авторы: Panikorovskii Taras L., Chukanov Nikita V., Aksenov Sergey M., Mazur Anton S., Avdontseva Evgenia Yu, Shilovskikh Vladimir V., Krivovichev Sergey V.
- Журнал: Mineralogy and Petrology
- Том: 111
- Номер: 6
- Год издания: 2017
- Издательство: Springer Verlag
- Местоположение издательства: Germany
- Первая страница: 833
- Последняя страница: 842
- DOI: 10.1007/s00710-017-0495-1
- Аннотация: Alumovesuvianite (IMA 2016-014), ideally Ca19Al(Al,Mg)(12)Si18O69(OH)(9), is a new vesuvianite-group member found in the rodingite zone at the contact of a gabbroid rock with host serpentinite in the abandoned Jeffrey mine, Asbestos, Estrie Region, Qu,bec, Canada. It occurs as prismatic tetragonal crystals up to 4 x 4 x 6 mm(3) in size encrusting walls of cavities in a granular diopside. Associated minerals are diopside, grossular and prehnite. Single crystals of alumovesuvianite are transparent colorless or light pink with a vitreous lustre. The dominant crystal forms are {100}, {110}, {210}, {111}, {101} and {001}. The Mohs hardness is 6.5. The specific gravitiy is D (meas) = 3.31(1) g/cm(3) and D (calc) = 3.36 g/cm(3), respectively. The mineral is optically uniaxial (-), omega = 1.725(2), epsilon = 1.722(2). The chemical composition, determined by SEM-WDS (wavelength-dispersive spectroscopy on a scanning electron microscope; all oxides except H2O) and TG (thermogravimety; H2O) analysis, is: SiO2 37.1 wt%, Al2O3 18.8 wt%, CaO 36.6 wt%, MgO 2.48 wt%, Mn2O3 0.67 wt%, Fe2O3 0.22 wt%, H2O 2.61 wt%, total 98.5 wt%. The empirical formula based on 19 Ca atoms per formula unit and taking into account the MAS-NMR (magic-angle spinning nuclear magnetic resonance) data, is: Ca-19.00(Al0.92Fe3+ (0.08))(I 1.00)(Al9.83Mg1.80Mn3+ pound (0.25))(I 11.88)Si17.98O69.16(OH)(8.44) pound. The most intense IR absorption bands lie in the ranges 412-609, 897-1024, and 3051-3671 cm(-1). The eight strongest lines of the powder X-ray diffraction pattern are (I-d()-hkl): 22-2.96-004, 100-2.761-432, 61-2.612-224, 25-2.593-600, 20-1.7658-831, 20-1.6672-734, 21-1.6247-912, and 22-1.3443-880. Alumovesuvianite is tetragonal, space group P4/n, unit-cell parameters refined from the powder data are a = 15.5603(5) , c = 11.8467(4) , V = 2868.3(4) (3), Z = 2. The crystal structure has been refined to R (1) = 0.036 for 3098 unique observed reflections with |F (o)| ae<yen> 4 sigma (F) . The structure refinement provides the < Y1A-O > bond length of 1.916 and the scattering factor for the Y1 site of 16 e (-) , which is in good agreement with the total occupancy of this site as (Al0.73Mn3+ Fe-0.20(3+) (0.07))(I 1.00) pound and is confirmed by the Al-27 MAS NMR data. Alumovesuvianite is a new member of the vesuvianite group with Al3+ as a dominant cation in the Y1 site. The name alumovesuvianite is given to highlight the species-defining role of Al.
- Добавил в систему: Аксенов Сергей Михайлович