Site occupancy refinement of osumilite
نویسنده
چکیده
The structure of osumilite from Nain, Labrador, (NaO.14Ko.86)[12] (Mg1.44Feo.56)[6] (MgO.23Feo.16Alz.61)[4] (Si10.36AI1.64)[4] 030 is hexagonal with space group P 6/mcc, Go = 10.126(2), Co = 14.319(3)A, Z = 2 and Dx = 2.63 g/cm3, and was refined to R (unweighted) = 0.033 and R (weighted) = 0.026 using 590 nonequivalent reflections. The basic structure determined by Brown and Gibbs (1969) was confirmed. It was shown, however, that part of both Fez + and MgZ + enter theT2 position (T2 0 distance 1.772A) and are not strongly fractionated between this and the octahedral M position (M 0 distance 2.135 A). No other site contains MgZ + or Fez + in this osumilite.
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تاریخ انتشار 2006