Ref : CARCO
Natural blue pigment
Molar mass: 119,00
In glazes: cobalt carbonate is a very intense colouring agent.
It has the same action as the oxide, but it is more voluminous and dissolves more easily in glazes.
In engobes: Additions of 1-15% in a white engobe make it light blue to dark blue.
Cobalt salt, insoluble in water and soluble in acids, which decomposes under the action of heat.
With additions of between 1-3% of this salt, blue glazes of less intensity are produced than with the same proportion of cobalt oxide.
This salt is used because with it the colour can be better dosed and the weighing errors minor.