This article presents the study of phase formation at nonductile component interacting (diopside, alumina and pre-synthesized porcelain). Technical ceramic compositions with improved physical and mechanical properties are developed on the basis of these components. A theoretical research has been conducted, as a result of which a triple forecasting diagram is built in the system of diopside - alumina - porcelain. The diagram reflects 10 main areas with a major crystalline phase for the composition. Theoretical investigations are proved out by experimental data.