Research on Polymer-Filled Gems

Polymer filling technology has been widely applied to the processing of gems.In order to further study polymer－filled gems，the authors tested the gems samples sold on Liwan plaza from Guangzhou by magnifying inspection，ultraviolet fluorescence and infrared spectrum （IR）testing methods.Magnifying inspection on internal and external characteristics of fillings shows that almost all gems sold on the market are filled by polymer.Ultraviolet fluorescence results show that the fluorescence characteristics of polymer filled in the fracture and structural gap can be used as subsidiary technique for the polymer－filled gems.It is also proved that the polymer filled in gems is epoxy resin by IR.The IR spectra of poly－mer have sharp peaks about 4 060，3 060，3 035cm^－1 and three stronger peaks at the center of 2 970or 2 962cm^－1，2 929or 2 935cm^－1，2 870or 2 865cm^－1（2 859cm^－1 for aquamarine）.The IR spectra of different volume proportions of polymer filled in tourmalines show that the weak absorption peaks have no obvious change with the filling ratio increases at 3 056，3 034cm^－1，but the strong absorption peaks at 2 965，2 924，2 862cm^－1 become more sharp，and then fall to a gentle absorption valley.The clarity grading standard for polymer－filled tourmaline is suggested to apply for testing of polymer－filled gems.