This study presents the first structural report of natural isokite (calcium magnesium phosphate fluoride), with the formula CaMg(PO4)F0.8(OH)0.2 (i.e. some substitution of OH for F), based on single-crystal X-ray diffraction data. Isokite belongs to the C2/c titanite mineral group, in which Mg is on an inversion centre and the Ca, P and F/OH atoms are on twofold axes. The structure is composed of kinked chains of corner-sharing MgO4F2 octa-hedra that are crosslinked by isolated PO4 tetra-hedra, forming a three-dimensional polyhedral network. The Ca2+ cations occupy the inter-stitial sites, coordinated by six O atoms and one F anion.
|Original language||English (US)|
|Journal||Acta Crystallographica Section C: Crystal Structure Communications|
|State||Published - Sep 22 2007|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)