The solid-state synthesis method was used to manufacture the various pigment precursor powders used in this study. In the case of Er6MoO12, orange–yellow colours were observed at calcination temperatures of 1200 °C and 1300 °C with different soaking times. Examination of the X-ray diffraction pattern generated after heat treatment at 1200 °C for 2 h revealed the single-phase nature of the compound. However, when applied to unleaded commercial transparent glaze, the pigment powder changed to a light pink colour indicating instability of the pigment in the glaze.