Mineralogical and Mössbauer studies on the paramagnetic separate of Al-Kidirate meteorite

The paramagnetic fraction of the chondritic meteorite (Al Kidirate) has been studied by scanning electron microscopy (SEM) and Mössbauer spectroscopy at different temperatures. The mineralogical analysis indicates that the fraction consists mostly of olivine and pyroxene. The pyroxene is present in two restricted compositions; bronzitic orthopyroxene and clinopyroxene in the diopside-endiopside range. The Mössbauer measurements confirm the above characterization showing two paramagnetic doublets for olivine and pyroxene. The Mössbauer relative area under the resonance curve together with the atomic concentration derived from the microprobe data are used to derive the chemical formulae for orthopyroxene and clinopyroxene. The formulae derived using the two methods show good agreement.