Thermal analysis of the 1:1 mix of molybdite and cerussite first displayed the characteristic peaks of cerussite. There is a sharp endothermic peak at 300 °C, which occurs during the dehydration of hydrocerussite associated with cerussite. A second peak at 350 °C is the first step of cerussite’s dissociation into PbO*PbCO3. Later at 400 °C, a medium endothermic peak represents the second step of the dissociation into lead oxide. These transitions involve a decrease in mass, which occurs in steps. First, the dehydration of hydrocerussite is marked by its loss of constitutional OH and later is the freeing of carbon dioxide during the cerussite dissociation. The formation of wulfenite occurs at 520 °C, as observed in the exothermic peak. The reaction between lead oxides and molybdenum takes place at 500-600 °C, along with the formation of lead molybdate.