the glassy transition, at 550° C, a glassy phase separation occurs at 580° C, with the
appearance of one silicate-and one phosphate-rich phase. It is followed by the
crystallization of the major phase Na2CaSi2O6, from 610 to 700° C and of the secondary
phase, silico-rhenanite, at 800° C. The latter evolves from the phosphate-rich glassy phase,
which is still present after the first crystallization. In order to control the processing of glass …