Rapid detection of the authenticity of silver jewelry by laser induced shockwave plasma spectroscopy using Nd:YAG laser 1064 nm

Abstract

Identification of the authenticity of silver jewelry has been carried out by using laser induced shockwaves plasma spectroscopy (LISPS) method. In this study, a plasma was generated by laser firing Nd: YAG (1064 nm, 40 mJ, 7 Hz) at a pressure of 1.5 torr to the target surface. The study was made to distinguish 99.9 % silver samples, 92.5 % silver jewelry, and imitation jewelry. The emission spectrum obtained from the 99.9% silver sample shows similarities with the 92.5% silver jewelry. However, imitation jewelry does not show the resemblance and undetectable elements of Ag. The detection limit of Ag was 2.74 %. In 92.5% silver jewelry, the other detected elements are Fe and Cu, while in the imitation jewelry, the other detected elements are Fe, Cu, and Zn with varying wavelengths. For comparison, imitation jewelry was also analyzed by using X-Ray Difraction (XRD) method. The result of the XRD method shows that the imitation jewelry is identical to Cu-Zn crystal structure.