Beryllium-Diffused Treatment Sapphire with Blue Body Colour

A type of beryllium-diffused treatment sapphire with blue or light blue body colour has recently appeared on gem markets.The chemical compositions,Raman spectrum and the characteristics of UV-NIS absorption spectrum of 50beryllium-diffused treatment sapphires samples are investigated by using EPMA,LA-ICP-MS,laser Raman spectrometer and micro-optical fibre spectrometer.The testing and research reasults show that the minimum mass percent of beryllium is5.28×10^—6％ and the maximum is17.51×10^—6％ and the average is8.74×10^—6％ in the beryllium-diffused treatment sapphire samples.Generally,the samples contain all forms of baddeleyite melting or pseudomorph inclusions.Because of d—d electron transition in the Fe^3＋ion,the absorption spectrum band a （377,386,451nm）of the samples is formed.With the high temperature,the beryllium-diffused and induced vacancy colour center may result in the blue colour of sapphire.