Which ceramic compounds are used to produce blue pigments?

In the field of materials science, specifically regarding optical ceramics, blue pigments are produced using specific ceramic compounds. The primary compounds identified for this purpose are:

• Cobalt aluminate (${\text{CoAl}}_2{\text{O}}_4$)12
• Cobalt silicate (${\text{Co}}_2{\text{SiO}}_4$)12

These pigments are typically composed of oxide compounds combined with transition-metal elements. The blue colour is imparted through the absorption of specific wavelengths of light by these transition-metal species within the ceramic structure. While other blue pigments exist in broader industrial contexts—such as Prussian blue (an iron cyanide complex) and ultramarine—the cobalt-based compounds are the standard materials used to impart blue colour within the ceramic and glaze industry.21345