CaMgSi2O6-CaAl2Si2O8 equilibrium phase diagram. Phases at equilibrium for the chemical system CaMgSi2O6-CaAl2Si2O8 are shown as a function of chemical composition (weight percent CaAl2Si2O8) and temperature at 1 atmosphere pressure. The orange area indicates temperatures and compositions for which a single phase, magma, is present at equilibrium. The magma only region is bounded by saturation curves: saturation with diopside (Di) on the left and saturation with anorthite (An) on the right. Saturation curves like these are also called liquidus curves. The Di and An saturation curves meet at a single point called a eutectic point, which marks the lowest temperature that magam can exisit in this system. Areas that have the horizontal line pattern indicate temperatures and compositions for which two phases are in equilibrium. This diagram was determined experimentally by Norman Bowen in (1915) at atmospheric pressure (1 bar).