有无N_3的无色与近无色天然钻石的荧光与光谱特征研究

Study on the spectral and fluorescent characteristics of natural colorless and near-colorless diamonds with or without N_3

通过傅里叶变换红外(Fourier transform infrared,FTIR)光谱结合紫外-可见吸收光谱(UV-Vis absorption spectra)及钻石观测仪(Diamond View)对有无415 nm吸收的无色与近无色天然钻石进行较系统的荧光与光谱特征研究。结果表明:UV-Vis吸收光谱中具有明显415 nm特征吸收的样品所对应的FTIR吸收光谱中1 376~1 359 cm-1处都存在较强且尖锐的吸收峰。相反,UV-Vis吸收谱图中无明显415 nm吸收的样品相应的红外谱图的1 376~1 359 cm-1处无明显的吸收峰位。且部分无415 nm吸收峰的样品在Diamond View下其荧光的颜色可呈现为黄绿色、黄绿色中夹杂蓝色或呈单一的蓝色,因此钻石在Diamond View下荧光呈蓝色是否直接归因于其中的N3尚待进一步商榷。该结论可为合成钻石与天然钻石的鉴定筛选提供一定的技术支持。

A systematic study on the spectral and fluorescent characteristics of natural colorless and near-colorless diamonds with or without 415 nm absorption is carried out by combining with Fourier transform infrared （FTIR） spectra, UV-Vis absorption spectra and DiamondView. The results show that for samples with obvious 415 nm absorption in UV-Vis spectra, they have strong and sharp absorption peak at 1 376-1 359 cm-1 in corresponding FTIR spectra. On the contrary, for samples without obvious 415 nm absorption in UV-Vis spectra, they do not have obvious absorption peak at 1 376-1 359 cm-1 in corresponding FTIR spectra. Interestingly, some samples without 415 nm absorption peak have their fluorescence color under DiamondView as yellow green, yellow green mixed with blue or pure blue. Therefore, it needs further discussion to determine whether the blue fluorescence of diamonds under DiamondView is caused by N3 or not. The research conclusions can provide important technical support for the identification and selection of synthetic diamond and natural diamond.