Counterfeit gold identification using sound and image processing

Gold mine is one of the most frequently faked mine by using matters having similar property or color. Since copper has similar color and tungsten has similar chemical properties, these two matters are the most frequently used counterfeit golds. Purity of a gold can be determined by X-ray devices but it is very expensive. Jewelers current methods and fake currency detection methods which have been used for years with low cost is tried on counterfeit gold detection. When pure gold is hit by another metal, sound would be more thud. When the same experiment is conducted on counterfeit gold, the sound would be squeal. Furthermore, most counterfeit golds have brighter color than original gold. Pure gold has a unique and special color of its own which is called `gold yellow´. In this paper, original gold is differentiated from counterfeit ones by using sound and color difference. Mostly gold forgery is done by mixing gold and copper with proportion. As a progress of this project, density and other features will be used to differentiate alloy and pure gold.