一类绿松石仿制品的宝石学特征研究

发布时间：2018-04-26 19:26

本文选题：绿松石 + 绿松石仿制品　；参考：《光谱学与光谱分析》2016年08期

【摘要】：绿松石的仿制品由来已久,早期主要以染色压制碳酸盐为主,后期陆续出现天然矿物的绿松石仿制品,如染色磷铝石、染色玉髓以及染色菱镁矿等,这些仿制品普遍不具有天然绿松石的颜色和结构特征,物理和光学性质与天然绿松石也有较大差异。选取市场上新出现的一类绿松石仿制品为研究对象,采用常规宝石学测试方法、红外吸收光谱及X射线粉晶衍射重点对其矿物组成、宝石学性质以及结构特征进行了研究。研究结果表明:该类绿松石仿制品表面可见角砾状构造,铁线浮于表面,分布形态单一,蓝色样品上可见明显的深蓝色颗粒,白色样品上见少量黑色点状物质,为典型的压制处理特征,蓝色绿松石仿制品则经染色压制处理。此类绿松石仿制品折射率在1.54~1.58,较天然绿松石低并具明显的蓝白色紫外荧光,可作为鉴别其与天然绿松石差异的重要证据。X射线粉晶衍射说明该类绿松石仿制品主要由顽火辉石与石英组成。红外吸收光谱显示该类绿松石仿制品的吸收谱峰主要表现为顽火辉石的典型吸收光谱,在1 088和799 cm~(-1)附近的吸收峰则与石英中的Si—O和Si—O—Si伸缩振动有关;2 947和2 882 cm~(-1)附近的吸收峰与外来的有机树脂中CH_2的伸缩振动有关,1 736和1 510 cm~(-1)附近的吸收峰,则由C=O伸缩振动和CH_2的弯曲振动所致。
[Abstract]:The imitation products of turquoise have a long history. In the early stage they were mainly dyed to suppress carbonate. In the latter stage, natural mineral imitation of turquoise appeared successively, such as dyed aluminite, dyed chalcedony and magnesite, etc. These imitations generally do not have the color and structure characteristics of natural turquoise, and the physical and optical properties are also quite different from those of natural turquoise. A new class of turquoise imitation products in the market was selected as the research object. The mineral composition, gemstone properties and structural characteristics of turquoise were studied by conventional gemstone test method, infrared absorption spectrum and X-ray powder diffraction. The results show that there are breccia structure on the surface of this kind of turquoise imitation, iron wire floating on the surface, single distribution form, obvious dark blue particles on the blue sample, and a small amount of black spot substance on the white sample. The blue turquoise imitation was dyed and pressed. The refractive index of this kind of imitation turquoise is 1.54 ~ 1.58, which is lower than that of natural turquoise and has obvious blue-white ultraviolet fluorescence. It can be used as an important evidence to distinguish the difference from natural turquoise. X-ray powder diffraction shows that this kind of imitation turquoise is mainly composed of enstatite and quartz. Infrared absorption spectra showed that the absorption peaks of this kind of imitation turquoise products were mainly the typical absorption spectra of enstatite pyroxene. The absorption peaks near 1 088 and 799 cm ~ (-1) are related to the stretching vibration of Si-O and Si-O-Si in quartz. The absorption peaks near ~ (2 947) and ~ (2 882) cm ~ (-1) are related to those near ~ 1 736 and 1 510 cm ~ (-1) of CH_2 in organic resins. It is caused by the stretching vibration of Con O and the bending vibration of CH_2.
【作者单位】：中国地质大学(武汉)珠宝学院;中国地质大学(武汉)地球物理与空间信息学院;中国地质大学(武汉)地球内部多尺度成像湖北省重点实验室;
【基金】：国家自然科学基金资助项目(41272053) 中央高校基本科研业务费专项资金项目(CUGL120279)资助
【分类号】：O657;TS933

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