The hydroxyapatite obtained from most reaction mixtures displayed in Figures show XRD patterns (Figures ) corresponding to the Sr5(MnO4)3OH structure but with significant discrepancies in relative intensities compared to those expected from the tabulated structure. These patterns were recorded with a flat XRD holder geometry and exhibit especially an inversion of relative intensities between the {211} (2θCu = 29.9° / Q = 2.1 Å -1 ) and the {300} diffraction peaks