Study on the Vibration Spectra of Turquoise Imitation and Natural Turquoise from Zhushan County，Hubei Province
ZENG Xuan1, YANG Zhi-jun1,2*, LI Xiao-xiao1, LEI Xue-ying1, HUANG Shan-shan1, CHEN Yao-ming1
1. School of Earth Science and Engineering，Sun Yat-sen University，Guangzhou 510275，China
2. Guangdong Provincial Key Laboratory of Mineral Resource Exploration & Geological Processes，Guangzhou 510275，China
Abstract：China is rich in turquoise mineral resources, and is one of the major producing countries in the world. As a kind of famous jade, turquoise is deeply loved by people with its unique colour of green and structure, which also leads to a large number of optimally treated products and imitations in the market. Compared to the study of turquoise and its imitations, the current researches on turquoise and its imitations need further data accumulation. In this paper, natural turquoise and its typical imitations from Zhu County in Hubei province were studied. Using optical photograph, field emission scanning electron microscope and energy spectrum, infrared and Raman spectra, a comparative study was conducted from the perspective of color, microstructure and microstructure. Research results showed that natural turquoise’s color varies with, the “white-light blue-light green-yellow-green-blue” series of change; the crystal particles are very small, and they are micro-sized to nano-scale, and short columnar and lamellar grains can be seen. The colors of turquoise’s imitations are single, often for the green, and it’s mostly scattered granular aggregate, and its size and appearance are not uniform. Natural turquoise mainly contains Cu, Al, P, O and other elements, and occasionally contains a small amount of Zn, Fe and other elements, therefore, it is mainly copper and aluminum phosphate minerals. Most particles of the turquoise imitations mainly contain of C, O, Mg and occasionally contain a small amount of Ca element, therefore, it’s mainly composed of magnesium carbonate magnesite. In the comparative study of infrared spectrum, the infrared spectrum of natural turquoise 3 083～3 509 cm-1 area contains a large number of infrared absorption peaks corresponding to the ν(OH) and ν(H2O). There were infrared absorption spectrum peak corresponding to νas (CH2), which is related to dyeing. These infrared absorption spectrum peaks are also the effective Raman fingerprint peaks of natural turquoise and turquoise imitation. In the study of contrasting Raman spectrograms, there were usually scattering peaks of ν(OH)，ν(H2O)，ν(PO4) at ～3 470，～3 270，～1 039 cm-1 related to natural turquoise when the turquoise imitation was not. So, they are all effective Raman fingerprint peaks between natural turquoise and turquoise imitation. Based on color, microstructure, microstructure and vibration spectrum, natural turquoise and its imitations can be distinguished. At the same time, this kind of method also contributes to distinguishing the other kinds of jade and the treatment ones.
曾 璇，杨志军，李晓潇，雷雪英，黄珊珊，陈耀明. 湖北竹山天然绿松石及其仿制品的振动光谱研究[J]. 光谱学与光谱分析, 2019, 39(03): 834-839.
ZENG Xuan, YANG Zhi-jun, LI Xiao-xiao, LEI Xue-ying, HUANG Shan-shan, CHEN Yao-ming. Study on the Vibration Spectra of Turquoise Imitation and Natural Turquoise from Zhushan County，Hubei Province. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2019, 39(03): 834-839.
