Fayalite chemical composition

Present M sbauer Studies of Natural Pyroxenes and Olivines. Table IX gives the major element chemical compositions of the silicate minerals examined in this study. Table X compares the Mossbauer parameters of these minerals, while Figures 9-13 show representative Mossbauer spectra. Fayalite (Figure 9) is the only olivine in this group. The two lines are, however, somewhat broadened (0.35 and 0.39 mm./ sec.) compared with the width of natural iron foil lines observed with our source (0.24 mm./sec.) and suggest the near coincidence of two quadrupole-split doublets resulting from Mi and M2 sites. Analysis of this "two-line spectrum into a four-line spectrum in the manner described by Evans et al (11) could possibly yield parameters for the two iron sites, but this was not undertaken since both lines appear symmetric. The "two-line quadrupole splitting of 2.78 mm./sec. is somewhat smaller... 

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