Identification of Jadeite Filled with Inorganic Materials Using UV Fluorescence, Infrared Spectroscopy and LIBS Techniques

BACKGROUND Through visiting the jadeite market, the existence of inorganic material-filled jadeite is known, but there is a lack of identification basis due to rare references. OBJECTIVES To understand the identification characteristics of inorganic material-filled jadeite. METHODS Two types of inorganic materials, water glass and silica sol, were used to fill low-grade jadeite in the simulation experiment. Conventional gemological tests, fluorescence image observation with DiamondViewTM, Fourier transform infrared (FTIR) spectroscopy, and laser-induced breakdown spectroscopy (LIBS) were used to test the inorganic filled jadeite samples. RESULTS The transparency, color, density and structure of jadeite were improved after filling. Under the DiamondViewTM, the jadeite particles in the sample showed green fluorescence, and the filling around the cracks and between the particles displayed blue fluorescence with non-uniform distribution. Mid-infrared reflectance spectrum analysis showed that the spectra of silica sol and water-glass were slightly different from each other. The absorption peaks of the samples filled with inorganic materials at 1162cm-1, 1070cm-1, 949cm-1, 579cm-1, 529cm-1 and 470cm-1 gradually weakened, and the peak shape gradually became smooth or disappeared. In addition, the differences between the jadeite and inorganic filled jadeite can be determined by the near-infrared spectral morphology and the shape of the absorption peak changed in the range of 7062cm-1, 5204cm-1 and 4537cm-1. The laser-induced breakdown spectroscopy demonstrated that the content of the silicon in the jadeite filled with silicon sol or sodium and potassium water-glass was higher. The high potassium content was an important feature for the jadeite filled by sodium and potassium water-glass. CONCLUSIONS The samples effect of the simulation experiment needs to be improved, but the identification characteristics of the filled jadeite with inorganic materials are recognized, which has caused a further breakthrough in the enhancement and treatment of jadeite identification.