两种类型天然紫色翡翠的致色机理  

Color origins of two types of natural lavender jadeite jades

作　　者：韩文 刘洋[2] 张钧 陆太进 HAN Wen;LIU Yang;ZHANG Jun;LU Tai-jin(National Gems&Jewelry Administrative Centre,Beijing 100013,China;Pingzhou Lab,National Gemstone Testing Centre,Foshan 528251,China)

机构地区：[1]自然资源部珠宝玉石首饰管理中心,北京100013 [2]国家珠宝玉石质量监督检验中心平洲实验室,广东佛山528251

出　　处：《矿物学报》2020年第5期549-555,共7页Acta Mineralogica Sinica

基　　金：NGTC科研基金项目(编号:NGTCBJ18004,NGTC2019010)。

摘　　要：紫色翡翠是天然翡翠中的重要品种,具有很高的经济价值,其主要有2种类型,一种呈较纯的紫色,另一种为带有蓝色色调的紫色。为探究紫色翡翠的致色机理,除采用传统的谱学及化学成分分析外,本文重点采用电子顺磁共振(EPR)、X射线光电子能谱(XPS)等,对2种类型紫色翡翠致色机理、致色元素价态等进行深入研究。结果表明,2种类型紫色翡翠均为硬玉颗粒本身呈色。紫色样品致色与Mn有关(w(Mn O)=0.0035%~0.036%),紫外可见光吸收光谱具有由Mn导致的580 nm吸收带,电子顺磁共振分析显示其主要为Mn3+,而并非Mn2+。蓝紫色翡翠由Fe、Ti元素联合致色(w(Fe O)=0.039%~0.25%;w(Ti O2)=0.018%~0.17%),X射线光电子能谱分析显示其主要致色离子为Fe2+、Fe3+和Ti4+,认为蓝紫色翡翠为Fe2+-Ti4+和Fe2+-Fe3+电荷转移致色,由此导致紫外可见光吸收光谱中具530和610 nm的吸收带。The Lavender Jadeite Jade is an important variety of natural jades,with high economic value.There are two types of lavender jadeites,including the pure purple one and bluish purple one.In this paper,besides methods of traditional spectroscopy and chemical analysis,Electron Paramagnetic Resonance (EPR) and X-ray Photoelectron Spectroscopy (XPS) were specifically used to investigate the color origins and chemical valences of the chromogeneic elements of two types of lavender Jadeite jades.The results show that colors of both two types of lavender jadeites were caused by the jadeite particles themselves.For the pure purple jadeite jade,the color is related to the contained Mn(w(Mn O):0.0035%-0.036%) which causes the 580 nm absorption band of UV-VIS,mainly in form of Mn3+rather than Mn2+based on the EPR results.Both Fe and Ti (w(Fe O):0.039%-0.25%;w(Ti O2):0.018%-0.17%) resulted in the bluish purple color of the second lavender jadeite jade.The XPS analysis suggests that the major chromogenic cations are Fe2+,Fe3+,and Ti4+.It is believed that the Fe2+-Ti4+and Fe2+-Fe3+charge-transfers are responsible for the bluish purple coloration which causes the 530 and 610 nm absorption bands of UV-VIS.

关 键 词：紫色翡翠 电子顺磁共振 X射线光电子能谱 致色机理 

分 类 号：P579[天文地球—矿物学]