Sterling silver alloy was susceptible to form firescale in heat working

such as casting and welding.The formation mechanism of firescale in the sterling silver alloy has been discussed by analyzing the firescale structure using XRD and OM.The results show that the copper is oxidized selectively to form cuprous or cupric oxide on the surface with sterling silver alloy heated

including outer oxidization layer and inner oxidization layer.However

the inner oxidization layer would be left during the oxidized samples pickled in dilute sulfuric acid

which exhibits firescale after the sample polished.