The reported find of barium biotites at the Aspen cape of the Bolshoy Ishkul lake is the first one at the Urals. These minerals occur in labrador and bytownite biotite-amphibole gabbro forming non-metamorphosed inclusi-ons in blocks of serpentinite melange among metamorphic rocks of Ilmenogorsky complex. There ate two varie-ties of barium biotites: first - with a moderate Ba content (BaO 1.37 wt%), and second - the Ba-rich one (BaO 8.52 wt%). Their crystal-chermical formulas, calculated on 7 cations, are, respectively: I - (K_0,98 Ba_0.04)_1.02 (Mg_1.40 Fe²⁺_0.81 Fe³⁺_0.37 Ti_0.25 Al^VI_0.14 Mn_0.03 V_0.03)_3.01 (Si_2.74 AI^IV_1.26O₁₀) (OH)_1.37; II - (K_0.73 Ba_0.27)_1.00(Mg_1.63 Fe²⁺_0.54 Fe³⁺_0.43 Al^VI_0.19 Ti_0.19 Mn_0.02)_3.00 (Si_2.50 Al^IV_1.50O₁₀) (OH_1.72 C_10.04)_1.76 Previously, the barium biotites with similar com-positions have been described in Coldwell alkaline comple. (In Russian)

Библиографическая ссылка: Кориневский В.Г., Кориневский Е.В., Кориневская Г.Г. Бариевый биотит из Ильмен // Записки Российского минералогического общества. 2005. № 2005. С. 75-83.