Li - teniolite is a trioctahedral type of mica group with formula K_{0.87}Na_{0.03}Ca_{0.04}(Mg_{2.48}Li_{0.46}Al_{0.05})_{2.99} [Si_{3.6}Al_{0.4}]4O_{10}F_{1.9}O_{0.1}, sp. gr. C2/m, 1M polytype. An instantaneous high pressure was effected on the ground mica powder, which was compactly filled up in cylindrical copper ampule, placed in a charge of explosive , namely hexagon. The explosive pressure was equal to 400 atm and caused nearly instantaneous heating up of the examined sample. The sample was slowly cooled. The optical study of the sample indicated the matter along ampule to be highly nonuniform. The most affected core and less affected external parts of cylindrical sample were clear- cut singled out. Indices of refraction have considerably been changed (Ng = 1.548 for initial sample, Ng=1.536 for sample after explosive action). The explosive action to the Li-teniolite caused a displacement of reflections on its X- ray powder diffraction pattern toward the higher angles and a significant decreasing and broadening in their intensities.
The unit-cell parameters have been changed a_{init.}=5.291 Å a$_{expl.}$=5.220 Å ; b$_{init}$=9.156 Å b$_{expl.}$=9.111 Å ; c$_{init.}$= 10.12 Å ; c$_{expl.}$=9.79 Å. Calculating some unit-cell parameters according to the model advanced by [1] has been performed on the basis of bt and chemical analysis. The calculation revealed that the height of octahedral layer was decreased (ho$_{init.}$=2.00Å, ho$_{expl.}$=1.90 Å) causing enhancing of y angle which characterized extension of octahedral layer (y$_{init.}=57^{o}36$r, y$_{expl.}= 60^{o}$2r). As a result of flattening octahedra were strongly deformed (practically they were antiprisms). The spaces between atoms forming the rlidsr of these antiprisms (u$_{expl.}$=3.03 Å) were larger than those between atoms forming their staggered edges (s=2.79 Å). These changes in the octahedral layer induced the tetrahedral sheet to be more mobile. It can be adopted to its own dimensions by decreasing the swing angles of tetrahedra (a$_{init.}$=11054r, a$_{expl.}=10048r). The interlayer space was increased (h$_{init.}$=3.57Å , h$_{expl.}$= 3.63 Å).
Thus the instantaneous high pressure action introduced a strong distortion in a structure of Li-teniolite and the structure became less stable to the explosive action than that of F-flogopite [2]. This work was supported by RFFI grant N 94-05-16537a.
1. Dritz V.A.: Epigenesis and its mineral indicators. 1971,
96-109.
2. Grigorieva T.N.: Infrared spectroscopy and X-ray
analysis of minerals. 1981, 51-56.