Spectroscopic Characteristics Study of Morganite from Mozambique
YIN Zuo-wei1, LI Xiao-lu2, BAO De-qing1, CHEN Quan-li1*, ZHANG Miao1
1. Institute of Jewelry, China University of Geosciences, Wuhan 430074, China 2. Jiangxi Central South Jiangxi Institute of Geological and Mineral Exploration, Nanchang 330029, China
Abstract：In recent years, morganite is becoming more and more popular due to its special color. The morganite samples located in the Republic of Mozambique were detailedly analyzed for its basic properties, chemical composition characteristics and spectroscopy properties by laser ablation plasma mass spectrometry (LA-ICP-MS), ultraviolet-visible absorption spectra (UV-Vis-NIR), infrared spectrum (IR) and Raman spectroscopy. The color parameters of morganite samples including the main wavelength, saturation, and lightness were got by UV-Vis-NIR. Chemical composition test showed higher content of Li, Rb, Cs and Mn in samples and chemical formula was calculated as Be3.209 0Al2.075 7Li0.425Si5.664O18(Na0.142 0Cs0.131 6). Infrared spectroscopy showed that morganite structure vibration area is mainly in the fingerprint area 400～1 200 and 900~1 200 cm-1 for the vibration of the ring Si—O—Si, 550~900 cm-1 for Be-O vibration area, and 450~530 cm-1 for Al—O vibration area. Because the Cs element content is higher in sample morganite and Cs belongs to higher atomic number elements, its existence may move the vibration frequency of Si—O—Si rings to the low position. Raman spectra showed 1 065 cm-1 for Si—O inner vibration of non bridge oxygen, around 1 000 cm-1 for Be—O outer vibration of non bridge oxygen, 685 cm-1 for Si—O—Si inner vibration of deformation, 400 cm-1 for O—Be—O outer vibration of bending, 390 cm-1 for Al—O outer vibration of deformation, 320 cm-1 for Al—O outer vibration of bending.
Key words：Morganite;The Republic of Mozambique;Cchemical composition;IR;Raman
[1] HU Huan, WANG Ru-cheng, ZHANG Ai-cheng, et al(胡 欢, 王汝成, 张爱铖, 等). Acta Geologica Sinica(地质学报), 2006, 80(6): 1780. [2] Gilberto A. American Mineralogist, 1993, 78： 762. [3] Kim C C, Bell M I, McKeown D A. Physica B, 1995, 205: 193. [4] PAN Zhao-lu(潘兆橹). Crystallography and Mineralogy(结晶学和矿物学). 3rd ed.(第3版). Beijing: Geology Press(北京： 地质出版社), 1993. [5] PENG Wen-shi, LIU Gao-kui(彭文世, 刘高魁). Infrared Spectrum Atlas of Mineral(矿物红外光谱图集). Beijing: Science Press(北京： 科学出版社), 347. [6] QI Li-jian, YUAN Xin-qiang, CAO Shu-min(亓利剑, 袁心强, 曹姝敏). Journal of Gems and Gemmology(宝石和宝石学杂志), 2005, 7(4)： 21. [7] HU Xiao-hong, ZHOU Jin-chi(胡晓红, 周金池). Analytical Instruments(仪器分析)，2011, 6： 1. [8] Denis L. International Journal of Mining Science and Technology, 2012，22： 711.
