gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1958.031.240.03 The System Diopside-Anorthite—åkermanite Christiaan De Wys E. M.A., Ph.D. 1 Foster Wilfrid R. M.Sc., Ph.D. College of Engineering, Ohio State University, Columbus, Ohio, U.S.A.

Now at Ferro Corporation, Cleveland, Ohio.

 3 1958 31 240 736 743 Copyright © 1958, The Mineralogical Society 1958 Summary

The high-temperature phase equilibrium relationships in the system diopside-anorthite—åkermanite have been investigated by the quenching method. This system may be regarded as essentially a simple eutectic system. The eutectic is located at the composition 9 diopside:44 anorthite:47 åkermanite (by weight) and at a temperature of 1226° C. Åkermanite is a stable phase at least as low as this temperature. Triclinic anorthite is the only form of CaAl2Si2O8 encountered in the liquidus range of temperatures.