A strong flux that can cause the solubility of lead in low-sol glazes. Up to 5% 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. High lime glazes can create purples; high lime glazes with alumina can create purple sploges. Fired under reduction in an alkali glaze (with addition of tin it creates a copper red or sang de-boeuf. Glass jar is for illustration purposes only.