Fe2+ distribution in stavrolite structure (on Mossbauer spectroscopy data)

New data on intercrystal distribution of Fe2+ in stavrolite structure are obtained with an aid of nuclear gamma-resonance spectroscopy. The investigations were carried out on 15 one-phase samples, containing from 11.99 to 14.34% of FeO. NGR-spectra were taken by a spectrometer with electrodynamic vibrator in the regime of stable accelerations, the source being 57Co in Pb with an activity of 17 mC. The measurements were made at the temperatures of 77 and 298 K. The parameters of NGR spectra of samples are presented. The investigations indicated the presence of Fe2+ both in tetrahedral (Fe4) and octahedral positions (Fe6), inhabited mainly by aluminium, and presence of energetically non-equivalent tetrahedral positions of Fe2+