Mössbauer studies of structural features in tourmaline of various genesis

Nuclear gamma ray (Mossbauer) spectroscopy (ngr) was used to examine 114 samples of tourmaline from different deposits. The absorption curve shape of the ngr spectra was found to depend not only on tourmaline composition, but also on the character of cation distribution in the crystal structure. The complex superpositional nature of the spectra corresponds to a statistical distribution of iron ions, whereas a minimum number of doublets is observed in an ordered distribution of these ions in the structure. The existence of nonequivalent Fe sites with statistical cation distribution in Y and Z positions was confirmed by experiments on iron oxidation in tourmaline, temperature studies of quadrupole splitting, and probability analysis of formation of nonequivalent sites in accordance with the tourmaline structure.