高压高温处理CVD合成Ⅰb型黄色钻石的鉴定特征

Identification Characteristic of HPHT-Treated Yellow TypeⅠb CVD Synthetic Diamond

大多数合成Ⅰb型黄色钻石为高压高温合成类型,CVD合成Ⅰb型黄色钻石在国内至今鲜有相关报道。近期,NGTC深圳实验室在检测过程中首次发现了1颗经高压高温处理的CVD合成Ⅰb型黄色钻石样品。该CVD合成Ⅰb型黄色钻石样品的鉴定分析有助于高效检测疑难样本,对检测行业和规范珠宝市场有重要意义。通过测试CVD合成Ⅰb型黄色钻石样品的红外光谱、紫外-可见吸收光谱、紫外荧光图像和光致发光光谱等特征来总结其鉴定方法。结果显示,由[Si-V]缺陷导致的737、766 nm和946 nm处的发光峰,以及荧光图像上显示明显的条纹生长结构,是该类CVD合成钻石的重要判定特征;同时,未发现596 nm和597 nm双线发光峰、显示较弱的3123 cm-1吸收峰以及明显的3107 cm-1吸收峰、H3(503.2 nm)发光峰、N3(415.2 nm)发光峰可判定该CVD合成Ⅰb型黄色钻石样品后期经过高压高温处理。

Synthetic typeⅠb yellow diamonds are mainly grown by High Pressure High Temperature(HPHT)process,however,typeⅠb CVD synthetic yellow diamonds have rarely been reported so far.A yellow typeⅠb CVD syntheitc diamond sample was recognized for the first time in NGTC Shenzhen Laboratory during daily testing.It is critical for jewelry testing industries to summarize the identification characteristics of this yellow typeⅠb CVD synthetic diamond,which will be helpful to identify problematic samples efficiently in the future.The means to identify the yellow typeⅠb CVD synthetic diamond are summarized by collecting the infrared absorption spectrum,ultraviolet-visible absorption spectrum,ultraviolet fluorescence image and photoluminescence spectrum of the sample.The luminescence peaks at 737,766 nm and 946 nm attributed to[Si-V]defects,and the parallel growth striations observied under fluorescence were diagnostic proofs of CVD synthetic diamonds.No doublet peaks at 596 nm and 597 nm were found and weaker 3123 cm-1peak was detected,and the obvious 3107 cm-1 peak,H3(503.2 nm)emission and N3(415.2 nm)emission suggested that it has undergone post-growth high temperature annealing to remove the as-grown brown coloration.