The quest for the development of thermal barrier coatings in jet engines, which can withstand extremely high temperatures, is on the rise. Thermal barrier coatings are ceramics that enhance the performance and durability of turbine engines blades. Research in these TBCs is very important for the booming aviation industry. New problems arise once the operating temperatures of these coatings are increased. One of the challenges which this paper focuses on is calcium-magnesium alumino silicate (CMAS). CMAS is a combination of sand, dust, volcanic ash, and runway debris. At lower temperatures contaminants can cause erosive wear to the TBC when impacting as solid debris. At higher temperature CMAS begins to melt when in contact with TBC and infiltrates into the engine blades. The ultimate goal of this research is to shed light on the properties of CMAS and ways to decrease aircraft engine damage. This paper investigates the reaction mechanisms and chemical compositions for rare earth zirconates. The Co-precipitation technique is used to produce the zirconates and to analyze the reaction with CMAS as a function of varying ion size of the rare earth elements. Lanthanum, gadolinium and yttrium zirconates were successfully prepared in the process to find the best solution to this dilemma. The reaction effects and products are discussed further in this paper.