Zirconia-silica composites were prepared and the compositions of these materials were determined using X-ray scattering. Differential thermal analysis (DTA) was employed to observe the phase transition from the amorphous state to the tetragonal state for each composite. With suitable calibration, DTA was shown to be a useful technique for the determination of particle compositions up to 5% wt./wt. silicon. Raman spectroscopy was utilized to observe the crystalline phase at room temperature after thermal treatment. The transition from the tetragonal to the monoclinic phase, which occurs during cooling, was observed using Raman spectroscopy, but was not apparent using DTA.