Crystal chemistry of the low-symmetry (P4nc) vesuvianite from the Kharmankul' Cordon (the South Urals)

T. L. Panikorovskii, S. V. Krivovichev, A. A. Zolotarev, A. A. Antonov

Результат исследований: Научные публикации в периодических изданияхстатья

8 Цитирования (Scopus)

Аннотация

Crystal chemistry of low-symmetry vesuvianite from the Kharmankul' Cordon (in specimen from the Mineralogical Museum of the SPbU) has been studied by electron microprobe analysis, single crystal X-ray diffraction and infrared spectroscopy. The crystal structure have been refined in the Pnc space group (P4nc, a = 15.6218(8), c = 11.8775(6) Å, V = 2898.6(3) Å 3 ) to R 1 = 0.036. Chemical composition of investigated sample (wt %): SiO 2 38.22, Al 2 O 3 15.68, MgO 4.03, CaO 37.35, FeO 4.36, total 99.64. The crystal chemical formula can be written as Ca 19 (Al 9.70 Mg 1.48 Fe 1.30 3+ Fe 0.52 3+ ) 13 Si 18 O 69 (OH) 9 IR spectrum bands are 438, 476, 563, 607, 632(w), 800, 881, 918, 964, 1016, 3200(shoulder), 3435, 3530 cm -1 . Different occupancies of the YIa and YIb sites (92 and 8 %, respectively) results in dominant orientation of chains of the intra-channels sites along the c axis, which causes reduction of symmetry from P4/nnc to P4nc. Detected average length of the <Fe-O> bond for YIA position is 1.96 Å, corresponding to Fe 3+ in this position. The mineral-forming took place at temperatures lower that 300°C and the high oxygen fugacity, which is in good agreement with supposed conditions of the contact metasomatic rocks formation in the Kharmankul' Cordon area.

Язык оригиналаанглийский
Страницы (с-по)94-104
Число страниц11
ЖурналZapiski Rossiiskogo Mineralogicheskogo Obshchestva
Том145
Номер выпуска3
СостояниеОпубликовано - 1 янв 2016

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Предметные области Scopus

  • Геохимия и петрология
  • Геология
  • Экономическая геология
  • Химия материалов

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