Identification Characteristic of Purple Jadeite Treated with Bleaching, Filling and Dyeing

Abstract

To explore the identification characteristics of purple jadeite that is treated with bleaching, filling and dyeing, the gem microscope, refractometer, UV-Vis-NIR spectropho-tometer, XRF spectrometer, DiamondViewTM, FTIR and Raman spectrometer were used. The results showed that the internal structure of the purple jadeite samples treated with bleaching, filling and dyeing was destroyed, and epoxy resin was detected by infrared spectrometer and Raman spectrometer. Strong Raman peak at 1 596 cm-1 could be the characteristic peak of dyes. Luminescent images showed the characteristic blue-violet fluorescence of the polymers formed by epoxy resin and organic dyes. The UV-Vis spectra of the purple jadeite samples treated with bleaching, filling and dyeing showed the absorption band of 200-350 nm, the absorption peak at 409 nm and the absorption band near 569 nm.The internal structure of the jadeite stained by the purple polishing powder was not damaged, and the purple colour only stained on the surface since the powder particles only remained on the surface. The luminescent images showed pinkish purple fluorescence, which was caused by the purple polishing powder. The strong central absorption band at 558 nm and the weak central absorption band at 611 nm can be seen in the UV-Vis spectra, which are different from the natural purple jadeite.