Copper Oxide (Black)

CuO.  2% added to most glazes produces a clear green. In alkaline glazes the colour shifts to turquoise blue.  At 5% or more, metallic surfaces develop. Fired in a reduction atmosphere, red colours are achieved with ½% or less. To substitute for copper carbonate, use 71% of the recipe requirement.

Note: Glazes become increasingly susceptible to food acid attack as copper oxide levels increase.  

For more information on copper oxide, see the Digitalfire.com Reference Library of ceramic materials.

TOXIC IN RAW FORM.