Aluminum-Rich Apatite

See allHide authors and affiliations

Science  02 May 1969:
Vol. 164, Issue 3879, pp. 551-553
DOI: 10.1126/science.164.3879.551


More than 25 atomic percent of aluminum can susbtitute for other cations in the structure of apatite [A10(XO4) 6Z2]. Such a synthetic product was obtained by expelling volatile constituents (H2O and F) from morinite during thermal treatment. Infrared absorption spectra, chemical analysis, and x-ray powder diffraction demonstrate that the aluminum has two coordination numbers, and more than twice as much aluminum substitutes for calcium (A position) as for phosphorus (X position).