Cupric Oxide is a chemical compound which is commonly black or grey in color. Used mostly as a pigment, particularly in glass, enamel and ceramic glazes, this versatile chemical has many other everyday and industrial uses as well. Botanists know this chemical for its fungicidal properties. In addition, it is an antifouling agent, that is, it can be applied to the hulls of ships and boats to keep away bothersome plant and animal life (e.g. barnacles). Lab technicians are familiar with this compound as a component of Benedict's test which detects the presence sugar. It is involved in copper plating processes as well. Farmers know it as a mineral supplement for life stock. More technological applications for this copper compound are its use in rectifier diodes, photocells, light detectors and ceramic superconductors. It naturally has a photoelectric effect so that when it is exposed to light, an electric current results.