ABSTRACTA brief review of the past literature on the thermochemical study of silicates, aluminosilicates and borosilicates was prepared. The present study includes the development of five ternary “deformation eutectics”, which had the following compositions and deformation temperatures:Cones were made and deformation was studied in the same manner as used with standard pyrometric cones. All eutectics developed are within the 2 1/2 molecular per cent limit. Combination of eutectics were also made but no further lowering of temperature was noticed. The results were discussed with special stress laid upon the relation between the various eutect