5Ca(NO3)2 + 3(NH4)2HPO4 + 4(NH3•H2O) → Ca5OH(PO4)3 + 10NH4NO3 + 3H2O
Calcium nitrate react with ammonium hydroorthophosphate and ammonium hydroxide to produce pentacalcium hydroxotriorthophosphate, ammonium nitrate and water. The reaction takes place in a boiling solution.