无色-近无色高温高压合成钻石的谱图特征及其鉴别方法  

The Spectral Characteristics and Identification Techniques for Colorless and Near-colorless HPHT Synthetic Diamonds

作　　者：宋中华[1] 陆太进[2] 苏隽[1] 高博[1] 唐诗[1] 胡宁[1] 柯捷[1] 张钧[1] 

机构地区：[1]国家珠宝玉石质量监督检验中心,北京100013 [2]国土资源部珠宝玉石首饰管理中心,北京100013

出　　处：《岩矿测试》2016年第5期496-504,共9页Rock and Mineral Analysis

摘　　要：实验室发现大量小颗粒的无色高温高压(HPHT)合成钻石与天然钻石混杂镶嵌在各种饰品中,前人提出荧光和磷光特征是主要的快速区分特征,然而荧光、磷光特征的差异并不能完全将HPHT合成钻石与天然钻石区分开来。本文将常规的宝石学观察分析与多种高精度谱学测试相结合,对五粒不同的无色-近无色HPHT合成钻石样品进行深入研究。结果表明,五粒钻石在紫外可见吸收光谱无270 nm吸收或是只有极弱的270 nm吸收,随着颜色级别的降低,270 nm吸收越明显。红外光谱测试显示,各粒样品中都含有不等量的硼元素。光致发光光谱测试表明,HPHT合成钻石含有与微量N、Ni、Si等相关的晶格缺陷。超短波紫外光源激发下,所有的HPHT合成钻石都有强磷光,在钻石观察仪下可以观测到清晰的八面体和立方体分区特征。显然,不同的合成钻石的特征略有差异,但综合其荧光及磷光特征以及红外、紫外、光致发光光谱特征,可以准确地将无色HPHT合成钻石与对应的天然钻石区分开来。Melee-sized colorless HPHT synthetic diamonds mixed with natural diamonds in jewellery have been reported by gem testing laboratory. It was noted that the differences of the fluorescence and phosphorescence between natural and synthetic diamonds are the key features for quick screening in mixed diamonds. However, it is difficult to completely distinguish the two only by the differences of fluorescence and phosphorescence. In this paper, 5 colorless gemquality HPHT synthetic diamonds were systematically investigated and characterized using mutiple spectroscopic techniques, together with traditional gem testing techniques. It was found that 5 samples display no, or weak, 270 nm absorption band at the UV-Vis spectra, and the lower the color grade, the stronger the 270 nm absorption band.Infrared absorption spectra showed that all samples contain boron.The photoluminescence spectra revealed that the colorless HPHT synthetic diamonds contain N, Ni or Si-related lattice defects. Under irradiation of the ultra-short wavelength light, all samples phosphoresced strongly with blue-green color. Typical octahedral and cubic growth patterns can be clearly observed under the Diamond View？ imaging system. Although there are some differences between the samples, the HPHT synthetic diamonds can be accurately identified through careful analysis combining all features, particularly the spectral charateristics of phosphorescence and fluorescence, FTIR, UV-Vis, and photoluminescence spectra.

关 键 词：高温高压合成钻石 天然钻石 紫外可见吸收光谱 红外光谱 光致发光光谱 荧光和磷光特征 

分 类 号：O657.32[理学—分析化学] O657.33[理学—化学]