一种疑似合成钻石的天然钻石光谱学特征  

Spectroscopic Characteristics of a Natural Diamond Suspected of Synthetic Diamond

作　　者：朱红伟 程佑法 陈淑祥[2] 范春丽 李婷 刘海彬 赵潇雪 山广褀 李建军 ZHU Hong-wei;CHENG You-fa;CHEN Shu-xiang;FAN Chun-li;LI Ting;LIU Hai-bin;ZHAO Xiao-xue;SHAN Guang-qi;LI Jian-jun(Shandong Institute of Metrology,National Gold&Diamond Testing Center/Shandong Key Laboratory of Metrology and Measurement,Jinan 250014,China;Qilu University of Technology(Shandong Academy of Sciences),Jinan 250353,China)

机构地区：[1]山东省计量科学研究院,国家黄金钻石制品质量检验检测中心/山东省计量检测重点实验室,山东济南250014 [2]齐鲁工业大学(山东省科学院),山东济南250353

出　　处：《光谱学与光谱分析》2023年第6期1690-1696,共7页Spectroscopy and Spectral Analysis

基　　金：国家质检总局科技计划项目(2012QK258);山东省科技厅重点科技计划项目(2017GSF220015);山东省计量检测重点实验室开放课题(2021JLZ03)资助。

摘　　要：该研究团队在近期日常检测中发现一粒疑似合成钻石的天然钻石。该样品的质量为0.0295 g(0.14 ct),尺寸为3.32 mm×3.33 mm×2.08 mm,颜色级别为H,净度级别SI_(1),在正交偏光镜下具有异常消光现象。该样品在短波紫外灯下具有强的绿黄色荧光,并伴有强烈的绿黄色磷光现象,磷光持续时间50 s以上;傅里叶变换红外光谱仪测试确认该样品为Ⅱa型,在1400~400 cm^(-1)无明显吸收峰,在1970~2500 cm^(-1)处具有由C—C晶格振动所引起的吸收峰;紫外可见光谱仪测试未检测到415 nm吸收峰,显示270 nm吸收峰。上述特征疑似HPHT合成钻石。为确认该样品的成因,又对其做了部分光谱测试,采用De Beers研制的Diamond-view^(TM)测试样品的发光图像,该样品的发光图像呈蜥蜴皮状、蜂窝状;采用常温光致发光光谱仪测试,选用405 nm光源激发时,可见415、428和450 nm特征峰;选用365 nm光源激发时,可见415、428和450 nm特征峰以及氮空位中心(N-V)~0引起的575 nm特征峰,未见氮空位中心(N-V)^(-)引起的637 nm特征峰;采用低温液氮光致发光光谱测试,选用488和514 nm激发光源,可见由氮空位中心(N-V)~0和(N-V)^(-)引起的575和637nm特征峰,并且575 nm峰强度远大于637 nm峰强度。总结对比当前最新的研究成果:415 nm特征峰是天然无色钻石的重要特征峰;CVD合成钻石具有737 nm光致发光特征峰;HPHT合成钻石具有882和883 nm光致发光特征峰;经HPHT处理钻石具有575和637 nm光致发光特征峰,且637 nm发光峰强度远大于575 nm强度。通过对比天然、合成和处理钻石Diamond-view^(TM)测试的发光图像特征,测试样品的发光图像符合天然钻石的特征。综合以上研究,最终确认该样品为天然Ⅱa型钻石。该样品研究表明,钻石鉴定需从常规宝石学特征入手,注重红外吸收光谱、紫外-可见光谱的测试,特别关注Diamond-view^(TM)荧光成像、光致发光光谱分析方法的使用,综合判断才�Our research team recently found a natural diamond suspected to be a synthetic diamond during routine testing.The weight of the stone was 0.0295 g(0.14 ct),the size of which was 3.32 mm×3.33 mm×2.08 mm,the color grade was H,the clarity grade was SI_(1),and there was abnormal extinction under the orthogonal polarizer.The sample had strong green-yellow fluorescence under short wave ultraviolet lamp,presented strong green-yellow phosphorescence,and the phosphorescence duration was more than 50 s.Fourier transform infrared spectrometer confirmed that the sample wasⅡa type,there was no obvious absorption peak between 1400~400 cm^(-1),and there was an absorption peak caused by C—C lattice vibration between 1970~2500 cm^(-1).UV-VIS Spectrometer did not detect the 415 nm absorption peak,but 270 nm absorption peak could be observed.The above characteristics were suspected tobe an HPHT synthetic diamond.In order to confirm the sample formation,some spectral tests were carried out.The luminous image of the sample was tested by using Diamond-view TM from De Beers.The testing showed that the luminous image of the sample was lizard skin and honeycomb.The constant temperature Photoluminescence spectrum of the sample found absorption peaks at 415,428 and 450 nm under 405 nm excitation source.The peaks of 415,428,450 and 575 nm caused by nitrogen-vacancy Center(N-V)0 could be obtained,but 637nm absorption peak caused by nitrogen vacancy Center(N-V)was not found under the 365 nm excitation source.Ata low-temperature liquid nitrogen condition,the photoluminescence absorption peaks of 575 and 637 nm caused by nitrogen-vacancy centers(N-V)0 and(N-V)-could be determined by using 488 and 514 nm excitation sources,and the 575 nm peak intensity was much stronger than 637 nm peak intensity.The latest research results were summarized and compared:The 415 nm characteristic peak is an important characteristic of a natural colorless diamond.The diamond synthesized by CVD has a characteristic photoluminescence peak of 737 nm.HPHT synthet

关 键 词：天然钻石 Ⅱa型 荧光 磷光 光致发光 

分 类 号：O433.3[机械工程—光学工程]