辐照处理前后阿富汗锂辉石的颜色变化和三维荧光特征  

The Colour Change and Three-Dimensional Fluorescence Features of Spodumene from Afghanistan Before and After Electron Irradiation

作　　者：杨雯斯 陈美华[1,2] 王小涵 孟迎欣 YANG Wensi;CHEN Meihua;WANG Xiaohan;MENG Yingxin(Gemmological Institute,China University of Geosciences,Wuhan 430074,China;Hubei Gems and Jewelry Engineering Technology Research Center,Wuhan 430074,China;Henan Core-Diamond Material Technology Co.,Ltd.,Zhengzhou 450000,China)

机构地区：[1]中国地质大学(武汉)珠宝学院,湖北武汉430074 [2]湖北省珠宝工程技术研究中心,湖北武汉430074 [3]河南碳真芯材料科技有限公司,河南郑州450000

出　　处：《宝石和宝石学杂志（中英文）》2024年第4期40-48,共9页Journal of Gems & Gemmology

基　　金：国家自然科学基金(41672043);中国地质大学(武汉)珠宝检测技术创新中心开放基金项目(CIGTWZ-2022018)。

摘　　要：目前天然产出的锂辉石可使用辐照改色的方法来达到提升其价值的目的,但是对于辐照锂辉石的谱学特征等信息并不完备。本文旨在通过电子辐照前后锂辉石的光谱特征分析其内部缺陷变化,为锂辉石缺陷分析及改色工艺提供一定的支撑。利用紫外-可见光光谱、荧光光谱对电子辐照前后浅紫粉色以及浅黄色阿富汗锂辉石样品进行分析,并对比荧光及磷光变化特征。结果显示,电子辐照后浅紫粉色锂辉石样品转变为翠绿色,粉橙色荧光明显增强,并出现粉橙色磷光;电子辐照后浅黄色锂辉石样品黄色调增加,大部分样品荧光无明显变化,而少数样品局部变为翠绿色,并在变色区域可见粉橙色荧光与磷光;紫外-可见光光谱显示辐照后呈翠绿色的锂辉石均在630 nm处出现吸收峰,浅黄色锂辉石辐照后局部变翠绿色,其Fe^(3+)吸收峰减弱;三维荧光光谱结果表明,电子辐照前后锂辉石样品中有λ_(em)=450 nm、λ_(em)=610 nm及λ_(em)=700 nm荧光区,辐照后荧光区存在不同程度的增强,辐照后变为翠绿色锂辉石有λ_(ex)=350 nm和λ_(ex)=600 nm荧光中心增强现象,这与强粉橙色荧光出现的现象相吻合。通过判断紫外-可见光光谱中是否存在630 nm处吸收峰以及三维荧光光谱中是否存在明显的λ_(ex)=350 nm和λ_(em)=600 nm荧光中心(粉橙色荧光)可以辅助判断锂辉石是否是经过辐照处理。At present,natural spodumene can be modified by irradiation to improve its value,but the information about the spectral characteristics of irradiated spodumene is incomplete.This study aims to analyze the internal defect changes of spodumene through its spectral characteristics before and after electron irradiation,so as to provide certain support for the defect analysis and colour modification process of spodumene.In this study,the light purple-pink and light yellow spodumene samples from Afghanistan before and after electron irradiation were analyzed by UV-Vis spectrum and fluorescence spectrum,and the fluorescence and phosphorescence changes of spodumene before and after irradiation were compared.The results show that after electron irradiation,the colour of the light purple-pink spodumene samples change to emerald green,the pink-orange fluorescence is obviously enhanced,and the pink-orange phosphorescence appears.The light yellow spodumene samples showed an increase in yellow tone and no significant change in fluorescence,while a few yellow samples partially became emerald green,and pink orange fluorescence and phosphorescence were seen in the discolored areas.The UV-visible spectrum results show that the samples show emerald green after irradiation show absorption peak at 630 nm,and the Fe^(3+)absorption peak of the samples that showed partially emerald green after irradiation was weakened in the light yellow samples.Three-dimensional fluorescence spectrum results show that there are λ_(em)=450 nm,λ_(em)=610 nm and λ_(em)=700 nm fluorescence regions in spodumene samples before and after irradiation,and the fluorescence regions are enhanced in different degrees after irradiation.Among the λ_(em),it is worth noting that after irradiation,the spodumene that changes into emerald green has an enhanced fluorescence center of λ_(ex)=350 nm and λ_(em)=600 nm,which is consistent with the phenomenon of strong pink orange fluorescence.By judging whether there is a 630 nm absorption peak in the UV-Vis spectrum and

关 键 词：锂辉石 电子辐照 荧光光谱 紫外-可见光光谱 阿富汗 

分 类 号：P575.4[天文地球—矿物学] TS93[天文地球—地质学]