The interior and the fusion crust in Saricicek howardite: Study using X-ray diffraction, magnetization measurements and Mossbauer spectroscopy

The meteorite Saricicek, a 2015 howardite fall in Turkey, was analyzed using various physical techniques. Both the interior and the fusion crust were studied by optical and scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction, magnetization measurements and Mossbauer spectroscopy. The main and minor iron-bearing phases such as orthopyroxene, Ca-poor and Ca-rich clinopyroxene, chromite with hercynite, Fe2+ and Fe3+ ilmenite, troilite, alpha-Fe(Ni, Co), alpha(2)-Fe(Ni, Co) and gamma-Fe(Ni, Co) phases were identified. The ratios of Fe2+ occupancies in the M1 and M2 sites in the silicate phases as well as the equilibrium Fe2+ and Mg2+ cations distribution temperatures (T-eq) for orthopyroxene were estimated using X-ray diffraction and Mossbauer spectroscopy, which appeared to be in a good agreement: for example, T-eq were 886 and 878 K, respectively. The glass-like fusion crust of Saricicek consists of orthopyroxene with ferrous and ferric compounds that are likely products of combustion and melting. (C) 2019 Elsevier B.V. All rights reserved.