Kurchatovite from the Fuka mine, Takahashi, Okayama, Japan

Abstract

Kurchatovite, Ca(Mg, Mn, Fe)B₂O₅, was found in aggregate of borate minerals consist mainly composed of shimazakiite at the Fuka mine, Okayama, Japan. Kurchatovite was first described as a new mineral by Malinko et al. (1966) from Solongo, Siberia, Russia. This is the first report of kurchatovite in Japan. The chemical composition range of kurchatovite from Fuka showed from the near Mg end-member to the middle member of Mg and Fe. But Mn is almost no included. In this range, kurchatovite is formed a continuous solid solution. The unit cell parameters are a=36.29(3), b=11.14(1), c=5.497(4) Å.