TiO2above 4 mol% is an effective nucleating agent for CaO–P2O5glass which also contains substantial SiO2and Al2O3additions. Glass ceramics can be made from this glass using a single slow heating ramp with no need for a nucleating heat treatment step. Powder of this composition crystallizes rapidly to β‐Ca2P2O7, whereas bulk glass crystallizes from diphasic nuclei consisting of a central cubic Ca‐P‐Ti‐Si‐Al oxide phase surrounded by impure AlPO4dendrites. Metastable calcium phosphate grows on the AlPO4dendrites and later transforms