Abstract
Suzukiite from the Mogurazawa mine, Gunma Prefecture, Japan exhibits orthorhombic space group Cmcm, a = 5.3546(16), b = 15.249(5), c = 7.094(2) Å, Z = 2. Electron microprobe analyses yielded the empirical formula (Ba0.977Sr0.027)Σ1.004V1.013Si1.985O7. The crystal structure was refined to R = 0.0211. The crystal structure of suzukiite comprises BaO11 polyhedra, SiO4 tetrahedra, and VO5 square pyramids. The Si4O12 chain runs parallel to the c axis, and the VO5 square pyramids link the chains to form a layer parallel to the ac plane. Ba atoms are located in the interlayer region and stack alternatively with the silicate–vanadate layers. The coordination of Ba in suzukiite is considerably distorted owing to the tight framework of the silicate–vanadate layer. The b length of the unit cell of suzukiite is larger than that of haradaite, the Sr analogue, whereas the a and c lengths show no remarkable difference.
