Ceramic Colorants - Cobalt

Cobalt

Cobalt is commonly used in either its carbonate (CoCO₃) or its oxide (Co₃O₄) forms. In the presence of most fluxes, it yields blue colors ranging from low saturation pastels to high saturation midnight blues in both oxidation and reduction atmospheres. However, in the presence of magnesium, cobalt can become purple, pink or reddish blue depending on whether it was fired in oxidation (yields purple) or reduction. Cobalt is also commonly used in black glazes and in washes as decorative medium. Common saturation percentages for low saturation range from (.25 to .5%) and in high saturation from (1 to 2%).