光谱学与光谱分析, 2021, 41(2): 636, 网络出版: 2021-04-08
Study on Spectral Characteristics of Turquoise With Blue “Water Ripple” From Shiyan, Hubei Province
“Water ripples” turquoise Micro X-ray diffraction Infrared spectrum Raman spectrum Micro ultraviolet visible near infrared spectrum “水波纹”绿松石 微区X射线衍射 红外光谱 拉曼光谱 显微紫外-可见-近红外光谱
“水波纹”绿松石是一种在外观上呈现水波纹状花纹图案的天然绿松石, 产量稀少却深受消费者喜爱, 前人对绿松石的研究较丰富, 但对“水波纹”绿松石的研究较少。 对一块基底呈浅蓝白色, 条纹呈蓝绿色的“水波纹”绿松石样品用显微激光拉曼光谱仪、 显微红外光谱仪、 微区X射线衍射、 激光剥蚀电感耦合等离子体质谱仪、 扫描电镜、 显微紫外-可见-近红外光谱仪等测试其各种性能。 结果表明, 条纹区与非条纹区的主要矿物均为绿松石; 红外光谱和拉曼光谱均显示绿松石的光谱; 条纹区与非条纹区的化学成分不同, 条纹区Al2O3, SiO2, MgO, V, Co, Ni, U及Y, Mo, Cd的含量较非条纹区含量高, 而非条纹区P2O5, CuO, K2O及Na2O的含量较条纹区含量高; 扫描电镜微形貌显示, 条带区的晶体多为厚板状、 晶体颗粒大、 排列紧密, 几乎不可见孔隙, 非条带区的晶体多为大小不一的柱状、 碎片状, 杂乱排列, 可见孔隙; 微区X射线衍射表明条带区的结晶度较非条带区的结晶度高; 显微紫外-可见-近红外光谱表明条带区与非条带区的致色离子相同, 均在426和660 nm处有可见吸收峰, 致色离子均为Fe3+和Cu2+。 “水波纹”绿松石样品的谱学特征表明, 条纹处与非条纹处的颜色差异与致色离子没有明显关系, 而颜色及透明度差异与绿松石的结晶程度、 致密程度有主要关系, “水波纹”绿松石中绿松石结晶度的变化表明了绿松石形成环境的不稳定性, 结晶度的周期性变化表明了形成绿松石的外界环境具有周期性变化的规律, 为研究绿松石的颜色成因及绿松石的成矿环境提供数据支撑。
“Water ripple” turquoise is a kind of natural turquoise with water ripple pattern on its appearance, which is rare in production but popular among consumers. Previous studies on turquoise are rich, but less on “water ripple”. In this paper, a turquoise sample with the light blue-white substrate and blue-green “water ripple” stripe was tested by micro laser Raman spectrometer, micro infrared spectrometer, micro X-ray diffraction, laser ablation system inductively coupled plasma mass spectrometer (LA-ICP-MS), scanning electron microscope and micro ultraviolet-visible near-infrared spectrometer. The results show that the main minerals in the stripe and non-stripeboth are turquoise, and show the infrared spectra and Raman spectra of turquoise; The chemical composition of the stripe is different from that of the non-stripe. The content of Al2O3, SiO2, MgO, V, Co, Ni, U, Y, Mo and Cd in the stripe is higher than that of non-stripe, while the content of P2O5, CuO, K2O and Na2O in non-stripe is higher than that of the stripe; The results of SEM microtopography show that most of the crystals in the stripe area are thick plate, large crystal particles, closely arrangement and almost invisible pores, while the crystals in the non-stripe area are mostly columnar with different sizes, fragmentary, disorderly arrangement and visible pores; The results of X-ray diffraction show that the crystallinity in the stripe is higher than that in the non-stripe; The results of micro UV-vis-NIR show that the absorption peaks are at 426 and 660 nm, and the chromogenic ions are Fe3+ and Cu2+. The spectral characteristics of “water ripples” turquoise sample show that the color difference between the stripes and the non-stripes is not related to the chromogenic ions, while the color and transparency difference is mainly related to the crystallinity and density of turquoise. The change of the crystallinity in “water ripple” turquoise indicates the instability of the formation environment of turquoise, and the periodic change of crystallinity indicates that the surrounding environment of turquoise formation has the regularity. It provides data support for the study of color origin and the metallogenic environment of turquoise.