Study on Spectroscopic Characteristics of Turquoise Treated With
Phosphate and Porcelain
ZHAO An-di1, 3, CHEN Quan-li1, 2, 3*, ZHENG Xiao-hua2, LI Xuan1, 3, WU Yan-han1, 3, BAO Pei-jin1, 3
1. Jewelry College of China University of Geosciences (Wuhan), Wuhan 430074, China
2. Jewelry College of Western Yunnan University of Applied Technology, Tengchong 679118, China
3. Hubei Gems and Jewelry Engineering Technology Research Centre, Wuhan 430074, China
Abstract：In recent years, a new kind of “porcelain-added” turquoise has appeared in the market, which is very similar to the raw ore of turquoise. This kind of “porcelain-added” Turquoise uses inorganic binder phosphate or silicate as additives to fill the turquoise, to improve the porcelain degree of turquoise. Therefore, it is named after “porcelain-added” turquoise. The appearance of this kind of “porcelain-added” turquoise is very similar to that of natural turquoise. At present, the research on this type of turquoise is relatively weak. In this paper, the chemical composition characteristics and vibration spectrum characteristics of turquoise treated with phosphate “porcelain” were systematically studied and analyzed using conventional gemological instruments, infrared spectrometer, X-ray fluorescence spectrometer, UV-Vis spectrophotometer and fluorescence spectrometer. The results show that the turquoise treated with phosphate “porcelain” is an aphanitic structure, and its surface is mostly waxy glassy luster, with black or white lumpy color spots and iron wires. The average relative density (2.38) of turquoise treated with “porcelain” is less than that of natural turquoise with a similar appearance (2.60); The fluorescence is inert as a whole, but some Turquoise treated with “porcelain” will have blue and white fluorescence distributed along the micro cracks on the surface of the sample under the UV fluorescent lamp; X-ray fluorescence (XRF) spectrometer was used to test and analyze the composition of the sample. The main chemical composition of turquoise treated with phosphate “porcelain” deviated from the theoretical chemical composition value of natural turquoise, ω(Al2O3) is between 20.91% and 39.45%, ω(P2O5) is between 42.32% and 53.46%, ω(CuO) is between 6.54% and 11.38%, ω(feot) between 0.43% and 22.2%, ω(SiO2) is between 0.28% and 4.52%, ω(K2O) between 0.05%～0.36%; The P/Al ratio of turquoise treated with phosphate and porcelain is 1.47～2.10, which is generally higher than that of natural turquoise; The infrared absorption spectra of turquoise treated with phosphate “porcelain” mainly show the vibration spectra of crystal water, hydroxyl water and phosphate groups, and the vibration frequency is basically the same as that of natural turquoise; The UV-Vis spectra showed that the spectral peak position of phosphate treated Turquoise was slightly offset from that of natural turquoise, but the overall trend was the same; The fluorescence of the three-dimensional fluorescence spectrometer is weak, and the intensity of the fluorescence center varies widely.
Key words：Turquoise; “Porcelain-added” treatment; Gemological characteristics; Chemical composition; Spectral characteristics
赵安迪，陈全莉，郑晓华，李 璇，吴燕菡，鲍珮瑾. 磷酸盐“加瓷”处理绿松石谱学特征研究[J]. 光谱学与光谱分析, 2023, 43(04): 1192-1198.
ZHAO An-di, CHEN Quan-li, ZHENG Xiao-hua, LI Xuan, WU Yan-han, BAO Pei-jin. Study on Spectroscopic Characteristics of Turquoise Treated With
Phosphate and Porcelain. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2023, 43(04): 1192-1198.
