There is an interest in understanding the nature of fluoro-alumino-silicate glasses based upon the apatite stoichiometric composition and of potential within ionomer cements for dental applications. X-ray and neutron diffraction studies have been undertaken on some compositions of the glass, a key question remains in the context of those glasses where calcium is partially substituted by strontium. The glass, SiO2(0.32)Al2O3(0.21) P2O5(0.107)Ca/SrO(0.21)CaF2(0.14), has an unusual behaviour as a function of temperature: amorphous phase separation (revealed by small angle scattering [1]) followed by crystallisation of two phases. This proposal will cast light on the phase separation, and crystallization, as a function of temperature using the uniquely wide dynamic range of NIMROD.