- © 2016 Mineralogical Society of America
The synthesis of 10 Å phase via the reaction of talc plus water at 8 GPa and 500 °C was studied by in situ Raman spectroscopy using a diamond-anvil cell. The initial fast (2 h) incorporation of interlayer H2O molecules into the talc structure is traced by gradual growth of new OH stretching bands at 3592 and 3621 cm−1 and the shift of several framework bands. Further monitoring at HP-HT conditions over 7 h reveals gradual weakening of the 3592 cm−1 band, which can probably be related to the onset of the formation of “long-run” 10 Å phase through the appearance of silanol groups following the model proposed by Pawley et al. (2010), influencing the interlayer hydrogen bonding.