STRUCTURE OF WADALITE CA6AL5SI2O16CL3

Calcium chloride framework aluminosilicate, (Ca5.88Mg0.23)(Al4.26Fe0.46)Si2.00O15.68Cl2.64, Al5Ca6Si2Cl3O16 (ideal), M(r) = 793.9 (ideal), cubic, I43dBAR, a = 12.001 (2) angstrom, V = 1729 (1) angstrom3, Z = 4, D(m) = 3.01, D(x) = 3.056 Mg m-3, lambda(Mo Kalpha1) = 0.70930 angstrom, mu = 2.95 mm-1, F(000) = 1565, T = 301 K, R = 0.062 for 243 reflections with F greater-than-or-equal-to 3sigma(F). Wadalite is a new mineral found in a skarn xenolith in two-pyroxene andesite at a quarry in Fukushima, Japan. The structure consists of a framework of (Al,Si)O4 tetrahedra. A large cavity in the framework accommodates Ca-Cl-Ca linearly coordinated atoms.