Iwateite, Na₂BaMn(PO₄)₂, a new mineral from the Tanohata mine, Iwate Prefecture, Japan

Abstract

Iwateite, Na₂BaMn(PO₄)₂ is a new mineral, which was found in the manganese ore of the No. 3 (Matsumaezawa) deposit in the Tanohata mine, Tanohata Village, Iwate Prefecture, Japan. Iwateite has a glaserite structure, which occurs as granular to anhedral inclusions of 10-100 μm in the main constituent minerals in manganese ore and sérandite crystal. It is colorless with white streaks, non-fluorescent, and it displays very weak pleochroism. Iwateite crystallizes in the trigonal system and belongs to the P3 space group where, a = 5.3642(10), c = 7.039(2) Å, V = 175.41(8) ų, and Z = 1, with a calculated density of 4.06 g/cm³.