Thermal barrier coatings (TBCs), which increase jet turbine efficiency by insulating hot zone turbine blades from extreme temperatures, are susceptible to infiltration and delamination by molten calcium magnesium aluminosilicate (CMAS). CMAS composition influences melting range, infiltration depth into TBC coatings, and reaction products with TBCs. The effect light salts have on CMAS thermodynamic properties and crystal structure is currently ill studied. Hence, a model calcium iron alumino-silicate (CFAS) based on naturally-occurring CMAS from Arizona’s deserts, is doped with sodium and potassium. Herein, we investigate the melting point and crystallization of potassium and sodium doped CFAS compositions via differential scanning calorimetry and expect to observe depressed melting temperatures for light salt-doped compositions. Crystal structure changes in the doped compositions were characterized by x-ray diffraction. This study will further the understanding how CMAS compositions will react with TBCs, which will aid in the improvement of CMAS resistance, and lead to more efficient jet turbines.