gems, jadeite, fei cui, Myanmar, treated jadeite, fei cui

In recent years, a new type of treated fei cui that is bleached, filled and dyed has entered the gem market, with most showing vivid colours and high transparency. Ultra-high-resolution microscopy, polarised light microscopy, DiamondView and FTIR are used to compare traditional treated B+C jadeite jade with this new type of treated B+C jadeite jade, with analysis under Raman and UV-Vis. The results show that, due to severe bleaching, more resin in the filling and a different variety of resin, this new B+C jadeite jade has greater transparency than the traditional B+C type. The new B+C type is dyed with an organic agent. The resulting dyed jadeite jade has the same colour but a different tone, and might show a different UV-Vis spectrum. Most samples of this new B+C type do not show a 437 nm absorption line. FTIR spectra of the resin filling (with curing agent) in the new B+C type show a broad absorption peak centred at 1594 cm⁻¹ and an absorption peak around 4052 cm⁻¹. Raman spectra show peaks at 1595 cm⁻¹ and 1142 cm⁻¹.