F faces of apatite and its morphology: Theory and observation

Abstract

Eighteen connected nets have been determined for hydroxyapatite, and 12 different F faces run parallel to at least one of these connected nets. The order of morphological importance of these F faces is determined by the slice energy, Eslicehkl and compared to the morphological data for natural apatites. It is found that there is a close agreement between predicted and observed morphology. It follows that the lowering of the apatite symmetry (P63/m → P21/b) due to the ordering of OH is not likely to be the cause of the occurence of plate like apatitic crystals in calcified tissues.