Used as a coloring agent in ceramics and glass to produce deep blue hues. Commonly employed in the production of pigments for paints, plastics, and tiles due to its stability at high temperatures. Acts as a catalyst in industrial processes such as hydrocarbon oxidation and in the desulfurization of petroleum. Utilized in the manufacture of rechargeable batteries, especially lithium-ion batteries, where it contributes to cathode materials. Also serves in the synthesis of other cobalt-containing compounds and in some solid-state reactions for electronic materials.