光谱学与光谱分析, 2018, 38 (9): 2872, 网络出版: 2018-10-02  

坦桑石的矿物学及谱学特征研究

Mineralogical and Spectral Characteristics of Tanzanite
赖萌 1,2,3廖宗廷 1,2,3杨如增 1,2,3周征宇 1,2,3钟倩 1,2,3
作者单位
1 同济大学海洋地质国家重点实验室, 上海 200092
2 上海宝石及材料工艺工程技术研究中心, 上海 200092
3 同济大学海洋与地球科学学院, 宝石及工艺材料实验室, 上海 200092
摘要
对来自坦桑尼亚Merelani地区的坦桑石样品, 分别采用电子探针、 EMXPLUS型ESR谱仪、 同步热分析仪、 紫外可见光谱仪以及傅里叶变换红外光谱仪进行了测试与分析。 结果表明: 坦桑石样品的主要成分为SiO2, Al2O3和CaO, 微量成分中V2O5含量相对最多, 平均含量为0.36%; 坦桑石样品本身不含吸附水, 结晶水, 加热至780 ℃附近时, 脱失结构水, 样品中结构水大约占总质量的2%; ESR实验结果中显示出明显Fe3+和Mn2+的电子顺磁信号; 紫外-可见光谱显示, 样品在385 nm处出现吸收窄带, 575和750 nm处分别出现较为宽缓的吸收; 红外光谱测试表明, 样品在6 500~9 000 cm-1波段的倍频振动区, 基本没有吸收。 在4 000~6 500 cm-1波段主要为和频振动, 5 956 cm-1附近呈较宽缓的吸收峰, 5 413, 5 184, 4 336和4 046 cm-1处出现较尖锐的吸收峰, 主要可能由O—H, 矿物内的Si—O, 以及空气里面的H2O分子和CO2振动所引起。 综合EPMA以及ESR分析结果, 蓝-紫色坦桑石颜色可能主要由V3+和V5+共同引起, Fe3+晶体场的d—d电子跃迁、 Fe2+→Ti4+的电荷转移辅助致色。
Abstract
In this paper, the Tanzanite samples from Merelani Tanzania have been respectively tested and analyzed by electron probe, EMXPLUS ESR spectrometer; SDT, UV VIS spectrometer and Fu Liye transform infrared spectrometer. The results show that: the Tanzanite samples are mainly composed of SiO2, Al2O3 and CaO, V2O5 has the content of 0.36%, which is the most trace components; TG-DTA curves show that there is no absorption water and crystal water in Tanzanite samples, when being heated to 780 ℃, the structural water is lost, the water in the samples is about 2% of the total mass; ESR results shows obvious Fe3+ and Mn2+ electron paramagnetic signal; UV Vis spectra shows that an narrow- band absorption appears at 385 nm while a wide- band absorption appears respectively at 575 and 750 nm; infrared spectra shows that there is no absorption in 6 500~9 000 cm-1 of the Tanzanite samples. The 5 956 cm-1 is a wide absorption peak, and there is a sharp absorption peak respectively at 5 413, 5 184, 4 336, and 4 046 cm-1, which are mainly caused by the O—H, the Si—O within in the minerals as well as H2O and CO2 inside the air environment. Based on the results of EPMA and ESR analysis, the color of blue-violet Tanzanite may be mainly caused by V3+ and V5+, d—d electron transition of the crystal field of Fe3+ and charge transfer of Fe2+ to Ti4+ to assist coloration.

赖萌, 廖宗廷, 杨如增, 周征宇, 钟倩. 坦桑石的矿物学及谱学特征研究[J]. 光谱学与光谱分析, 2018, 38(9): 2872. LAI Meng, LIAO Zong-ting, YANG Ru-zeng, ZHOU Zheng-yu, ZHONG Qian. Mineralogical and Spectral Characteristics of Tanzanite[J]. Spectroscopy and Spectral Analysis, 2018, 38(9): 2872.

关于本站 Cookie 的使用提示

中国光学期刊网使用基于 cookie 的技术来更好地为您提供各项服务,点击此处了解我们的隐私策略。 如您需继续使用本网站,请您授权我们使用本地 cookie 来保存部分信息。
全站搜索
您最值得信赖的光电行业旗舰网络服务平台!