抄録
The crystal structure of masutomilite from Tanakamiyama, Ohtsu, Japan, has been refined by the X-ray single crystal method. The chemical formula is (K1.79 Na0.15 Rb0.14)2.08 (Li2.54 Mn0.992+ Fe0.182+ Fe0.063+ Al1.96 Ti0.01)5.74 (Si6.65 Al1.35)8.00 O19.64 (F3.16 (OH)1.20)4.36 and the crystal data are as follows: monoclinic, C2, a = 5.262(2), b = 9.102(3), c = 10.094(3)Å, β = 100.83(2)°, Z = 1. The final R-value converged to 0.046 (wR = 0.052), using 519 independent reflections. The octahedral cation ordering, small Al and Fe3+ in the M(2) site, and the remaining large Li and Mn2+ in the M(1) and M(3) sites, results in the non-centrosymmetric C2 structure. The mean bond length of M(2)–O is 1.89Å, and those of M(1)–O and M(3)–O are 2.13 and 2.12Å, respectively.
