Analysis Of Luminescence Characteristics Of Different Genetic Types Of Diamonds

In order to explore the luminescence and fluorescence spectrum characteristics of different genetic types of diamonds,and provide innovative detection methods for nondestructive and rapid identification of diamonds,this paper analyzed the luminescence of colorless,yellow and red diamonds of different genetic types,including natural diamonds,CVD synthetic diamonds,HPHT synthetic diamonds and diamonds treated by irradiation or HPHT The luminescent characteristics of the samples were determined by Diamond ViewTM and cathodoluminescence.The spectral characteristics of the samples were analyzed by infrared spectrum and photoluminescence spectrum.The fluorescence characteristics and luminescent spectrum specificity of different genetic types of diamonds were explored.In colorless series,natural IaAB,IaB diamond and HPHT synthetic Ib diamond show moderate blue fluorescence under ultraviolet fluorescent lamp,and blue green fluorescence under Diamond View TM,which is related to the internal N3 color center;The colorless diamond synthesized by CVD is inert under UV fluorescence,and shows blue purple and orange red alternate layer luminescence in parallel distribution under Diamond View TM.The photoluminescence spectrum shows the related[Si-V]-and[N-V]central absorption peaks.The three-dimensional fluorescence spectra of colorless series show double fluorescence peaks along the first-order Rayleigh line,and the best excitation is in the range of 304nm-370nm,which is consistent with the UV fluorescence characteristics of the corresponding blue-green region.In the yellow series,the natural IaAB diamonds and the natural IaAB diamonds treated by HPHT or irradiation are mostly yellow green and blue-green under UV fluorescence,which are related to their internal N3 and H3 centers.The synthesis of Ib yellow diamonds by HPHT is fluorescence inert due to the inhibition of fluorescence by catalyst.The natural IaAB yellow diamond shows yellow green fluorescence under Diamond View TM.After irradiation and HPHT treatment,the IaAB diamond shows the loading strong dislocation slip characteristics of HPHT treatment on the basis of overall green blue fluorescence.The photoluminescence spectra of the yellow series all show strong nitrogen related emission peaks at 575nm and 637nm,indicating[NV]0 and[N-V]-centers,and Ni related emission peaks at 646nm appear in the Ib type samples synthesized by HPHT.The three-dimensional fluorescence spectra of the yellow series show double fluorescence peaks along the first-order Rayleigh line and strong fluorescence peaks in the range of 470-650nm.The optimal excitation wavelength is 370nm and the corresponding emission wavelength is 560nm,which is consistent with the yellow green fluorescence displayed in the LWUV.In the red series,HPHT synthetic ?b diamond,HPHT-treated ?aAB natural diamond and CVD synthetic ?aB diamond which is HPHT and irradiation treated show orange-yellow and orange-red fluorescence under ultraviolet fluorescent,along with orange-red fluorescence under Diamond View TM.The fluorescence color is related to the internal NVO center and NV-center.The threedimensional fluorescence of red series samples shows three peaks,and the best excitation is near 518nm(?EX)/721nm(?EX)in orange and red regions,accompanied by a wide fluorescence band in the range of 560-820nm,which is consistent with the orange-yellow and orange-red fluorescence of the series under LWUVIt can be concluded from the above research that the most effective detection methods for different colors and types of diamonds are different,and the luminescent characteristics can be combined with the spectral characteristics to provide a reference for the identification of natural,synthetic and optimized diamonds.