Laser cleaning of unwanted jewelry patina

Women's necklace-filigree with patina, of unknown age, owned by a private collection was cleaned with a Nd:YAG laser. Laser parameters were varied during the experiment; wavelength, fluence and number of pulses, ie irradiation time. The influence of the mentioned factors on the efficiency of laser cleaning of the patina was investigated. The ablation results were examined by optical microscopy. The test results showed that the most efficient cleaning is with l = 1064 nm. The choice of fluence has the greatest influence on the efficiency of laser cleaning, for the mentioned subject, and the influence of the number of laser pulses has a smaller influence.