When synthesised at high pressure and temperature, holmium germanate adopts the pyrochlore structure. Because of its geometry, materials with this structure often have exotic and interesting magnetic properties. Normally, the pyrochlore structure is only stable when the two metals are relatively similar in size, which is not the case for Ho and Ge. This explains why extreme conditions are required to make it. In this experiment we will use the Pearl diffractometer to follow the conversion of a mixture of the simple component oxides to the pyrochlore as we increase temperature and pressure. We have also recently made a sample of holmium germanate in a different crystal structure and hope to use this as a precursor phase that can be converted to the pyrochlore at lower temperature or pressure than the simple oxide approach.