Gold Plating on Metallic Optical Frames and Jewellery

Abstract

Gold is a relatively scarce yellow metal often found in the native State, which is the most valuable of all metals. It is extremely corrosion resistant but it may be dissolved by aqua-regia, Potassium cyanide solution and in aqueous solution of the halogens. The metal does not form a coherent oxide film on its surface even at very high temperature and therefore, it has a very low contact resistant. First of all the Gold plating was done by the ancient Egyptians, but this was only a thin hammered film on other metals, in the middle ages the process called fire gilding was used to ‘plate’ objects.