A strong flux that can cause the solubility of lead in low-sol glazes. Copper carbonate is weaker than Copper oxide but is easier to mix reducing the risk of speckle. 3-7% in the carbonate will give an apple green colour under both oxidising and neutral conditions; yellow-greens in a potash glaze; blue-greens in a barium glaze; turquoise blue in an alkaline glaze.
