The wollastonite formulation falls within the triangle compatibility of CaO·SiO2-3CaO·2SiO2-2CaO·Al2O3·SiO2, with an eutectic at ~1310°C, while feldspar formulation lies in neighboring triangle CaO·SiO2-2CaO·Al2O3·SiO2-CaO·Al2O3·2SiO2, with an eutectic at ~1265°C.