Comparison of the Fe-57 hyperfine interactions in silicate phases in Saricicek howardite and some ordinary chondrites

Silicate crystals have different thermal history in non-differentiated and differentiated meteorites. This leads to some differences in the Fe2+ and Mg2+ distribution between the M1 and M2 sites in olivine, orthopyroxene and clinopyroxene crystals in stony meteorites resulting in small variations in the Fe local microenvironment. For this reason, a comparison of Mossbauer hyperfine parameters for the Fe-57 in the M1 and M2 sites in orthopyroxene and Ca-rich clinopyroxene for non-differentiated NWA 6286 LL6, NWA 7857 LL6 and Tsarev L5 ordinary chondrites and differentiated Saricicek howardite was carried out. The results obtained demonstrated small variations in quadrupole splitting and isomer shift for the studied non-differentiated and differentiated stony meteorites.