Stability of phlogopite quartz and diopside

Stability of Phlogopite, Quartz and Diopside Superposing Boyd s (1959) curve for the reaction Ca2Mg5Si70s022(0H)2 2CaMgSi205 + 3MgSi03 + Si02 + H2O (Ph,Sa,L) tremolite diopside enstatite quartz gas 

This diagram, as drawn, makes the following assumptions. 

There is a constant ratio of 1 1 between K O and A1 0 in the phases sanidine, phlogopite, and liquid. Quartz and 0-rich gas 

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