Effect of alkaline and alkaline earth ratios on the colour development of malayaite-based ceramic ink

In this study, pink colour development was investigated by changing systemically alkaline and alkaline earth ratios of the developed glaze. Group-1 (Na2O/CaO, Na2O/MgO, Na2O/BaO) and Group-2 (CaO/MgO, CaO/BaO) represent compositional variations. Group-1 has alkaline oxides with changing ratios of 0.2 mol Na2O and 0.6 mol CaO and 0.2 mol Na2O and 0.2 mol BaO, respectively. These ratios vary as 0.2 mol CaO and 0.1 mol BaO in Group-2. According to the results, the pink colour intensity was improved in the compositions with cassiterite (SnO2) and malayaite CaSn(SiO5) phases. In addition, bar-shaped BaO–CaO–Al2O3–SiO2 crystals were observed in structures with high barium oxide content. It could be concluded that the pink colour development regarding the a* (redness) value may also be related to the presence of BaO–CaO–Al2O3–SiO2