Suzukiite, Ba2V24+(O2|Si4O12), a new mineral from the Mogurazawa mine, Gumma Prefecture, Japan.

Abstract

Suzukiite, Ba2V4+2[O2|Si4O12], orthorhombic, Amam or Amam2, a=7.089(2), b=15.261(2), c=5.364(1)A, Z=2, is a new mineral corresponding to the barium analogue of haradaite, Sr2V4+2[O2|Si4O12].The electron microprobe analysis gave : BaO 38.38, SrO 3.21, VO2 23.56, TiO2 0.20, SiO2 33.59, total 98.94%, yielding the empirical formula (Ba1.78Sr0.22) Σ2.00(V4+2.02Ti0.02)Σ2.04Si3.97O14 on the basis of O=14.It is bright green in colour with a vitreous lustre and pale green streak. Cleavages {010}, perfect; {100} and {001}, distinct. Specific gravity 4.0(obs.), density 4.03g/cm3(calc), H. (Mohs) 4 to 41/2 on {010}. It is optically biaxial negative, 2V about 90°, r<v, very strong. Refractive indices: α=1.730(5), β=1.739(calc), γ=1.748(5). Optical orientation and axial colours: a=X=pale green, b=Y=light yellowish green, c=Z= bluish green.Suzukiite is found in massive rhodonite-rhodochrosite ore from the bedded manganese ore deposit of the Mogurazawa mine, Kiryu City, Gumma Prefecture, Japan, in association with quartz, barite, nagashimalite and a barian roscoelite.