Kozoite-(Nd), Nd(CO3)(OH), a new mineral in an alkali olivine basalt from Hizen-cho, Saga Prefecture, Japan

Kozoite-(Nd), Nd(CO3)(OH), occurs in cavities and fissures of alkali olivin e basalt exposed at Niikoba, Hizen-cho, Higashi Matsuura-gun, Saga Prefectu re, Japan, in association with lanthanite-(Nd) and kimuraite-(Y). The cryst al structure was refined by the Rietveld method in space group Pmcn; a = 4. 9829(1), b = 8.5188(2), c = 7.2570(2) Angstrom, Z = 4 using powder diffract ion data obtained by a combination of a Gandolfi camera and monochromatic s ynchrotron radiation. Kozoite-(Nd) is pale pinkish-purple to white with a v itreous to powdery luster. The calculated density is 4.77 g/cm(3). It has h igh birefringence, alpha = 1.698(2), gamma = 1.780(5). The four strongest l ines in the X-ray powder patterns [d(Angstrom), I/I-0, hkl] are (4.29, 100, 110); (2.93, 89, 102); (2.33, 78, 131) and (2.06, 78, 221). Kozoite-(Nd) i s the first naturally occurring RE(CO3)(OH) end-member in the ancylite grou p.