3. What is the Eutectic composition? At what temperature is the eutectic point? Label this point with an (E) on the diagram to the right. What phases exist as the eutectic? If a melt with a composition at the red square is cooled until 1400C. What is the composition of the melt, solid phases at this temperature? What is the proportion of solid and melt at this temperature? If the system continues to cool until 1274C, just as the system reaches the eutectic point, what is the composition of the phases?

1553 1550 1500 Liquid 1450 Temperature C 1400 1391 Liquid + An 1350 Liquid + Di 1300 1274 1250 Diopside + Anorthite 20 80 0 CaMgSi 206 Di 40 60 Weight % An 1200 100 CaAl 25i 208 An