A black prismatic kobeite-like mineral from a granite pegmatite of the Ushio mine in Omiya town, Kyoto Prefecture and the kobeite from the original locality have been studied. Both the chemical analyses and the X-ray powder patterns of heated materials of the two minerals gave the concordant results. The two minerals contain notable amount of zirconium and after heat treatment give X-ray patterns similar to those of stabilized cubic zirconia. Kobeite will not be a member of the

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... e series but may be a distinct mineral species of multiple oxide containing Y, Fe, U, Ti, Zr and Nb as the main components.