Phase Relations in the System Na2Si2O5-SiO2

Science  18 Jun 1965:
Vol. 148, Issue 3677, pp. 1589-1591
DOI: 10.1126/science.148.3677.1589


A new compound, Na6Si8O19, is shown to be a thermodynamically stable phase in the Na2O-SiO2 system at 1 atmosphere. The new compound melts incongruently to SiO2 (quartz) and liquid at 808° ± 2°C, and it disproportionates to βNa2Si2O5 and quartz at 700° ± 10°C.