台湾蓝玉髓宝石矿物学特征及颜色成因分析  

Research on Gem Mineralogical Characteristics of Taiwan Blue Chalcedony

作　　者：吴欣茹 何雪梅[1] 陈康琳 汪心怡 申南玉 WU Xinru;HE Xuemei;CHEN Kanglin;WANG Xinyi;SHEN Nanyu(School of Gemmology,China University of Geosciences(Beijing),Beijing 100083;Department of Natural Resources of Yunnan Province,Kunming 650224)

机构地区：[1]中国地质大学(北京)珠宝学院,北京100083 [2]云南省自然资源厅,昆明650224

出　　处：《中国宝玉石》2020年第5期20-25,共6页China Gems & Jades

摘　　要：本文以台湾蓝玉髓为研究对象,通过常规宝石学测试、偏光显微镜下观察、红外光谱测试、拉曼光谱测试、紫外一可见光光谱以及XRF荧光光谱分析,对样品的宝石学特征进行分析,并进一步对其颜色成因进行了探讨。结果表明,台湾蓝玉髓为蓝绿色,块状构造,隐晶质结构,半透明到微透明,点测折射率1.51~1.53,紫外荧光下呈惰性。其主要矿物为石英,次要矿物为硅孔雀石、褐铁矿等。红外光谱显示典型石英质玉石的振动峰。拉曼光谱除了显示石英振动峰外,还出现了680cm^-1、800cm^-1、1055cm^-1、1600cm^-1附近的硅孔雀石特征峰以及502cm^-1处的斜硅石的拉曼位移,说明蓝玉髓中还含有硅孔雀石和斜硅石。紫外一可见光光谱显示样品在210~350nm、650〜900nm具有吸收,匹配为Cu^2+的吸收带,XRF荧光光谱分析结果表明Cu^2+的含量与玉髓蓝色的浓度有关,推测Cu^2+是台湾蓝玉髓的主要致色元素之一。In this paper,Taiwan blue chalcedony is studied by conventional gemological tests,polarizing microscope,infrared spectra,Raman spectra,ultraviolet visible spectra and X-ray fluorescence spectra to analyze the gemological characteristics and the color mechanism of the sample.The results show that Taiwan blue chalcedony is blue-green,massive structure,aphanitic structure,glass luster,translucent to slightly transparent,with the refractive index of 1.51〜1.53,UV fluorescence inertia.The main mineral is quartz,and the minor minerals are chrysocolla and limonite.The infrared spectra show the vibration peak of typical quartz jade.Raman spectra show the vibration peak of quartzite,the characteristic peaks of chrysocolla at 680cm^-1,800cm^-1,1055cm^-1 and 1600cm^-1 and the Raman shift of moganite at 502cm^-1,which indicates that blue chalcedony contains chrysocolla and moganite as well.The UV-Vis spectra show that the samples reveal absorption at 210~350nm and 650~900nm,which matches the absorption band of Cu^2+.The results of X-ray fluorescence spectra analysis show that content of Cu^2+ is related to the coloration of blue chalcedony.It is speculated that Cu+is one of the main chromogenic elements of Taiwan blue chalcedony.

关 键 词：台湾蓝玉髓 红外光谱 拉曼光谱 硅孔雀石 XRF 

分 类 号：P575[天文地球—矿物学]