Co3O4 A very powerful colorant and flux for glazes (<2%) and slips (<10%) typically producing deep clear blues but also pinks, mauves and greens. Produces transparent blue-greens with copper oxide, opaque blue greens with chrome oxide, purples with CrSn Crimson stains and blacks with multiple oxides. If used as a recipe substitute for cobalt carbonate, use 67% of the recipe amount.
For more information on cobalt oxide, see the Digitalfire.com Reference Library of ceramic materials.