Hizenite-(Y) and rhabdophane-(Y), new minerals from the Higashimatsuura basalt, Kyushu, Japan

Abstract

The Higashimatsuura basalt is a Neogene alkali basalt distributes in the Higashimatsuura peninsula, Kyushu, Japan. REE minerals were reported in this basalt (e.g. kimuraite, Nagashima et al., 1986). In this study, two new minerals which approved by IMA are reported. Hizenite-(Y), ideally Ca₂Y₆(CO₃)₁₁•14H₂O is orthorhombic, and lattice parameters are a = 6.295 (1) Å, b = 9.089 (2) Å, c = 63.49 (1) Å. It occurs as a aggregate of very thin platy crystal. Rhabdophane-(Y), ideally YPO₄•H₂O is hexagonal, and lattice parameter is a = 6.959 (2) Å, c = 6.384 (2) Å. It occurs as a radial aggregate of short rod like crystal.