Normally known as GPC or
PGC, is the most important gold source in electrolytic gold
plating. The salt, KAu(CN)2, is generally obtained by anodic dissolution of
gold in an aqueous solution of potassium cyanide and subsequent crystallization.
It usually contains about 68 per cent fine gold and has the appearance of a white
powder that dissolves in water. Well over one hundred tonnes of GPC is manufactured
annually for use both in the electronics
industry for plating contacts or connectors and for decorative plating of costume
jewellery, watches and pens.