NaAlSi3O8-CaAl2Si2O8 equilibrium phase diagram. Phases at equilibrium for the chemical system NaAlSi3O8-CaAl2Si2O8 are shown as a function of chemical composition (weight percent CaAl2Si2O8) and temperature. The orange area indicates temperatures and compositions for which a single phase, silicate liquid (magma), is present at equilibrium. The liquid only region is bounded by a single saturation curve for plagioclase (Pl). Plagioclase is a solid solution phase. The green area indicates temperatures and compositions for which a single phase, plagioclase, is present at equilibrium. The plagioclase only region is bounded by a single saturation curve for liquid (Liq). Areas that have the horizontal line pattern indicate temperatures and compositions for which two phases, plagioclase and silicate liquid, are in equilibrium. This diagram was drawn from data obtained in high temperature experiments by Bowen (1913) and revised by Morse (2015).