Thermal analysis for molybdite and lead oxide mixes at a 1:1 ratio suggest that the formation of wulfenite occurs at 500 °C, as can be seen by an exothermic peak at this temperature. Microscopic investigation of the products show that at 500 °C, wulfenite is the main product, while at 950 °C, wulfenite is the only constituent of the product, as grains of molybdite and lead oxide melt and undergo volatilization. A small endothermic peak at 640 °C may represent the start of vaporization, and a sharp and large endothermic peak at 980 °C indicates the melting and volatilization of the unreacted lead and molybdenum oxides.