摘 要: | Opaque minerals in the Jilin meteorite inelude kamacite, taenite troilite, chromite, ilmenite, schreibersite, pyrite, pyrrhotite, chalcopyrite, sphalerite and graphite.Five of the above-mentioned minerals have been discussed in more detail in terms of optical and physical properties, chemical composition, coexisting relationship, and the order of crystallization. It is indicated from this study that, with the exception of a small amount of Ni-Fe cbondrules, silicate minerals are the first to erystallize followed by chromite, ilmenite at the early stage of nebula condensation, while Ni-Fe phase in the matrix is considered to be of a more later erigin. At the late stage of nebula condensation troilite resulted from the reaction of Ni-Fe metal with residual H2S vapor. As indicated by the occurrence of coarse grained Ni-Fe metal, the recrystallization of troilite and the apparent Neumann lines in kamaeite, it is expected that opaque minerals in the Jilin metevrite have undergone different degrees of thermal and impact metamorphisms.
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