来自四个产地的红色系尖晶石的光致发光光谱定量分析及其产地溯源  

Quantitative Analysis of Photoluminescence Spectrum of Red Spinel from Four Localities and Its Application in Provenance Tracing

作　　者：周纪玲 王成思[2,3] 叶宇 沈锡田[2,3] ZHOU Jiling;WANG Chengsi;YE Yu;Andy Hsitien Shen(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China;Gemmological Institute,China University of Geosciences,Wuhan 430074,China;Hubei Gems and Jewelry Engineering Technology Research Center,Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)地质过程与矿产资源国家重点实验室,湖北武汉430074 [2]中国地质大学(武汉)珠宝学院,湖北武汉430074 [3]湖北省珠宝工程技术研究中心,湖北武汉430074

出　　处：《宝石和宝石学杂志（中英文）》2024年第S01期46-49,共4页Journal of Gems & Gemmology

基　　金：广东省基础与应用基础研究基金区域联合基金-青年基金项目(2022A1515110780);第74批博士后面上项目(2023M743293)。

摘　　要：宝石级尖晶石是重要的彩色宝石品类,近年来如曼辛、纳米亚、马亨盖等产出高价值尖晶石的小产地涌现,使尖晶石的产地价值愈发凸显。同时,近五年与尖晶石产地鉴别相关的论文数量较上一个五年增长了约200%,是当前行业关注的热点课题。目前,相关研究主要集中在运用地球化学分析和包裹体特征来进行产地溯源,但仍存在如判别特征重叠和高品质单晶包裹体缺失等问题。因此,深入探究尖晶石的晶体性质并将之应用于快速无损检测之中,有利于助力开发适合我国质检行业的尖晶石产地溯源技术,对我国宝石学研究和行业发展均具有重要的意义。尖晶石的光致发光光谱由一系列复杂N峰组成,其中每一个N峰都对应着一种光致发光中心Mg^(2+)和Al^(3+)占位的排布情况,这为后续尖晶石光致发光光谱的应用奠定了坚实的基础^([1-6])。本课题组基于尖晶石的有序-无序相变特征,在前期研究中已证明尖晶石的光致发光光谱中R峰(有序峰)和N峰(无序峰)的比例可以反映其无序程度,并建立了热力学模型实现定量计算其热历史(封闭温度)^([7])。在上述理论基础上,本研究以缅甸、坦桑尼亚、越南和塔吉克斯坦四个产地共308颗红色系尖晶石样品(图1)为研究对象,主要研究成果如下:(1)研究方法适用范围验证。本研究证明尖晶石中Cr含量低于LA-ICP-MS的检测限,也可能探测出尖晶石中Cr^(3+)的PL光谱(图2)。这表明尖晶石中Cr^(3+)具有极高的PL效率,证明了本研究方法也可以应用于其他颜色尖晶石的研究;(2)基于定量和定性分析方法,汇总各产地尖晶石Cr^(3+)的光致发光光谱特征,并筛选出具有产地鉴别意义的光谱特征。在液氮测试条件下,各产地尖晶石位于零声子线(14480~14640 cm^(-1))范围内均会分裂出N_(1)、n_(3)、N_(2)和n 5共四个峰。除此,塔吉克斯坦尖晶石样品还会分裂出n_(1)峰,坦桑尼�Gem-quality spinel is an important category of gemstones.Currently,deposits such as Mansin,Namya,and Mahenge,known for yielding high-value single spinel crystals,have appeared.Over the past five years,there has been over 200%increase in the number of papers related to spinel compared to the previous five years.Current research mainly focuses on using geochemical analysis and inclusions characteristics for provenance tracing;however,there are shortcomings such as overlapping discriminant features and the absence of inclusions in gem-quality spinel.Therefore,delving into the crystallographic properties and its application in rapid non-destructive testing of spinel are conducive to the developing provenance tracing technologies suitable for the domestic quality inspection industry,which is of great significant for the domestic gemmological research and industry development.PL spectrum of spinel is constituted by a series of N-lines,each of which is associated with the arrangement of PL centers of Mg^(2+)and Al^(3+)in spinel.This laid a solid foundation for the application of PL spectrum of spinel.Based on the ordered-disordered phase transition characteristics of spinel,our research group has demonstrated in preliminary studies that the ratio of the R peak(ordered peak)to the N peak(disordered peak)in PL spectrum of spinel can finely reflect the degree of disorder,and established a thermodynamic model to quantitatively calculate its thermal history(closure temperature).In this study,308 red spinel samples from Myanmar,Tanzania,Vietnam,and Tajikistan(Fig.1)were studied.The main results are as follows:(1)Validation of method applicability.This study has demonstrated that even when chromium content of spinel is below the detection limit of LA-ICP-MS,and may also detect the PL spectrum of Cr^(3+)within the spinel(Fig.2).This indicates extremely high PL efficiency of Cr in spinel,proving that our research method is not only applicable to red spinels but can also be broadly applied to the majority of gem-quality spinels.(

关 键 词：宝石级尖晶石 产地溯源 光致发光光谱 

分 类 号：TS933[轻工技术与工程] O657.3[理学—分析化学]