Abstract
Infrared spectra of synthetic potassio dioctahedral micas (muscovite-celadonite) indicate that ordering occurs in the two octahedral sites when more than 50 percent of the MgAl celadonite mica component is present. The appearance of doublets for certain vibrations suggests that there might be more than one type of Si-О network at intermediate compositions in the series. The Si-О apical vibration exhibits a single mode evolution. The vibrational energy-tetrahedral site occupancy relation for some other synthetic mica series shows that the energy of this band depends upon both the aluminum-silicon substitution and the structural type of mica involved. Octahedrally-coordinated ionic species do not seem to affect this vibrational energy. It seems that octahedral ions are not closely related to the apical oxygens in the Si-О network.
