Synthesis of A-type carbonated hydroxyapatite (CHA) materials has typically involved heating of a hydroxyapatite composition for 24 h or greater. In this study, a hydroxyapatite powder was heated at 800, 900 or 1000 degrees C for 1, 8 or 16 h in dry CO2. Samples heated for 8 and 16 h at 900/1000 degrees C were fully-carbonated A-type CHAs. After only one hour at 1000 degrees C, the carbonate content approached 95% of the theoretical maximum. Preparing compositions with more than 95% of the theoretical maximum with reduced thermal energy (1000 degrees C for 1 h, or 900 degrees C for 8 h) results in powders with higher surface areas and a reduced level of sintering, compared to powders prepared with typical thermal treatments reported for A-type CHAs, such as 1000 degrees C for 16 h. As far as the authors are aware, these are the shortest heating times reported for the preparation of fully-carbonated A-type CHAs which is significant for future applications of such powders, particularly in applications beyond medical devices such as chromatography, remediation and carbon capture. Crown Copyright (C) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.