Calcium phosphate powders of calcium pyrophosphate alpha(1)-CPP (the metastable phase of the high-temperature polymorph alpha-CPP) and the polymorph beta-CPP (stable in this range), of alpha(1)-CPP, beta-CPP, alpha(1)-TCP (metastable polymorph of the high-temperature phase alpha-tricalcium phosphate) and beta-tricalcium phosphate beta-TCP were prepared by heating amorphous calcium phosphate (ACP) precipitates with the nominal Ca/P ratio of 1:1 by nitrate synthesis. alpha(1)-CPP/beta-CPP resulted from a crystallization at 530-640 degrees C and subsequent heating to 980 degrees C of unwashed and lyophilized ACP. alpha(1)-CPP/beta-CPP/alpha(1)-TCP/beta-TCP was formed by crystallization at 620-720 degrees C, followed by heating of six-time washed and lyophilized ACP precipitates from an ultra-short synthesis. The activation energy for the crystallization of ACP to alpha(1)-CPP was determined with 165 kJ mol(-1). The reason for the occurrence of the TCP phases (Ca/P ratio=1.5) from ACP (Ca/P ratio=1) is discussed. The powders are prospective biomaterials for bone substitution because they combine effective bioactive phases with the metastable polymorphs alpha(1)-CPP and alpha(1)-TCP. (C) 2016 Published by Elsevier B.V.