CoO (Cobalt Oxide)

Notas

Cobalt oxide, represented by the formula CoO, functions as a highly potent and reliable colorant for glazes, glass, enamels, and ceramic pigments. Due to its intense coloring strength, even trace amounts can yield distinct blue hues, often necessitating dilution in a carrier material to facilitate accurate measurement and uniform dispersion. While various raw precursors exist, such as cobalt carbonate (CoCO3) or cobaltosic oxide (Co3O4), these decompose to form the stable cobaltous oxide (CoO) during the firing process. Although pure cobalt oxide has a high melting point, it integrates readily into most glaze matrices. It serves as an active flux, particularly in boron-based or alkaline glazes, which can increase local melt fluidity. This high reactivity may lead to the blurring of painted details or, at high concentrations, contribute to surface defects like crawling or blistering. Cobalt oxide remains chemically stable across a broad range of firing temperatures and atmospheric conditions, showing no significant volatility even at 1400°C. It is recognized for its exceptional color consistency, making it a standard component for underglazes, decal applications, and ceramic stains.