“加瓷”处理绿松石的成分及谱学特征研究  

Study on Composition and Spectral Characteristics of Turquoise Treated by“Porcelain-Added”

作　　者：黄莉莹 陈全莉[1] 高欣欣 杜阳 徐丰舜 HUANG Li-ying;CHEN Quan-li;GAO Xin-xin;DU Yang;XU Feng-shun(Gemmological Institute,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)珠宝学院,湖北武汉430074

出　　处：《光谱学与光谱分析》2021年第7期2245-2250,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(41272053);国家重点研发计划项目(2018YFF0215403);中国地质大学(武汉)珠宝检测技术创新中心基金项目资助。

摘　　要：近年来,市场上出现了一类利用新型无机结合剂处理的绿松石,经此类方法处理的绿松石与天然绿松石极为相似,普遍表现为结构细腻、呈现玻璃-蜡状光泽,行业上称之为“加瓷”处理绿松石(简称“加瓷”绿松石)。采取常规宝石学仪器、红外吸收光谱仪、紫外-可见分光光度计以及能谱色散型X射线荧光光谱仪对“加瓷”绿松石的宝石学性质、振动光谱特征以及化学成分组成特征进行了系统的研究和分析。研究结果显示:“加瓷”绿松石样品的密度大都小于2.200 g·cm^(-3),与处理前密度有关,故用于“加瓷”处理的样品以密度较低的绿松石为主;“加瓷”绿松石均表现为典型的低密度、较细腻的结构外观和蜡状-玻璃光泽的组合特征,与品质相当的天然绿松石特征不一致,可作为“加瓷”绿松石重要的辅助性鉴别特征。“加瓷”绿松石在长、短波紫外荧光下的发光性与天然绿松石近于一致;显微观察下铁线、裂隙凹陷处常出现白色融出物,孔道内可见毛发状结晶体。“加瓷”绿松石的主要化学成分与天然类似,以CuO,Al_(2)O_(3)和P_(2)O_(5)为主,并含有一定量的FeOT(铁的氧化物),ZnO、SiO_(2),K 2O和CaO。其中,“加瓷”处理绿松石样品中SiO_(2)含量基本在6.40%以上,均高于天然绿松石中的SiO_(2)含量(1.96%~6.25%),而Al_(2)O_(3)和P_(2)O_(5)含量都较天然绿松石偏低,磷铝比例基本与天然绿松石一致,为1.10左右。利用“加瓷”绿松石较高的SiO_(2)含量和表面特征可将其与天然绿松石进行有效鉴别。“加瓷”绿松石与天然绿松石的红外吸收光谱特征基本一致。“加瓷”绿松石的UV-Vis光谱表现为620~750 nm处的吸收峰以及425 nm附近处较为锐利的吸收峰,因颜色不同峰位稍有偏移,但总体与天然绿松石的UV-Vis光谱特征趋于一致。In recent years,a kind of turquoise treated with a new type of inorganic binder has appeared on the market.The turquoise treated by this method is very similar to the natural turquoise,which is generally characterized by a fine structure,glassy luster or greasy luster.It is called“porcelain-added”turquoise in markets.Conventional gemological testing instruments,infrared absorption spectrometers,UV-Vis spectrometers and energy dispersive X-ray fluorescence spectrometers were used to systematically study and analyze the gemological properties,vibration spectrum characteristics and chemical composition characteristics of“porcelain-added”turquoise.The results show that the density of turquoise samples treated with“porcelain”is mostly less than 2.2 g·cm^(-3),and its density is related to the density of turquoise before treatment.The samples treated with“porcelain”are mainly turquoise with a lower density.The turquoise treated by“porcelain”is characterized by typical low density,delicate structural appearance and strong wax-glass luster combination,which is inconsistent with the characteristics of natural turquoise and can be used as an important auxiliary identification feature of turquoise treated by“porcelain”.The luminescence of turquoise treated by“porcelain”under long-wave and short-wave UV fluorescence is nearly consistent with natural turquoise.Under microscopic observation,the white melting matter often appears in the iron wire and crevasses,and hair-like crystals can be seen in the pores.The main chemical composition of“porcelain-added”turquoise is similar to the natural turquoise,with CuO,Al_(2)O_(3) and P_(2)O_(5) as the main components,and containing a certain amount of FeOT,ZnO,SiO_(2),K 2O and CaO.Among them,the SiO_(2) content of the“porcelain-added”turquoise sample is basically above 6.40%,which is higher than that of the natural turquoise(1.96%~6.25%),and its Al_(2)O_(3) and P_(2)O_(5) contents are lower than those of the natural turquoise,and the proportion of pho

关 键 词：“加瓷”绿松石 红外吸收光谱 化学成分 紫外吸收光谱 宝石学特征 

分 类 号：P575.4[天文地球—矿物学]