Identification of Nephrite Gravel with Organic Imitated Skin
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摘要: 近期在软玉交易市场出现的一种仿仔料，以软玉山料、山流水料为原料，经磨圆处理后，通过有机材料在其表面形成一层人工伪皮。该种有机伪皮仿仔料的外观特征与带有天然风化皮的仔料极为相似，对消费者具有一定的欺骗性。采用常规宝石学测试手段结合电子探针和傅里叶变换红外光谱仪对仔料和有机伪皮仿仔料的常规宝石学性质、化学成分和红外光谱进行综合比对研究。研究结果表明，仔料与仿仔料的表面形貌特征、折射率、密度等常规宝石学性质存在区别，而紫外灯下发光特征一致。仔料风化皮的化学成分中FeOT含量高于未风化层，且FeOT含量随风化皮颜色的变浅显著降低；而仿仔料伪皮的化学成分无法由电子探针准确测定。仔料风化皮、未风化层和仿仔料未风化层均具透闪石的红外光谱特征；而仿仔料伪皮则显示高分子聚合物的红外光谱特征，其中1 730，1 452 cm-1附近的红外吸收谱带分别为v(C=O)和δ(C—H)所致。表面形貌特征观察、折射率测定并结合化学成分和红外光谱分析对该种有机伪皮仿仔料的鉴别具有一定意义。Abstract: Recently a kind of nephrite gravel (Ziliao in Chinese) imitation has appeared in the Chinese nephrite market. This nephrite gravel imitation is in fact primary nephrite (Shanliao in Chinese) or slope-wash deposit nephrite (Shanliushuiliao in Chinese), which was rounded off and further dyed and manufactured skin by using polymer materials. The appearance of this nephrite gravel imitation is close to nephrite gravel with weathering crust, so it may be deceptive to consumers. Thus, the conventional gemmological testing methods, EPMA and FTIR were used to compare the conventional gemmological characteristics, chemical composition, and infrared spectra between nephrite gravel and nephrite gravel imitation. The results show that, there are differences between nephrite gravel and nephrite gravel imitation, such as surface topography characteristics, refractive index and density, while the fluorescence of nephrite gravel and nephrite gravel imitation tend to be the same. EPMA analysis indicates that the chemical composition of weathering crust of nephrite gravel contains a higher content of FeOT than its fresh layer. However, the chemical composition of artificial crust of nephrite gravel imitation can hardly be precisely tested by EPMA analysis. FTIR analysis shows that both fresh layer and weathering crust of nephrite gravel have a characteristic infrared spectral feature of tremolite, so does the fresh layer of nephrite gravel imitation;while artificial skin of nephrite gravel imitation has a characteristic infrared spectral feature of polymer. The absorption bands relating to the vibration and bending modes of C=O and C-H in polymer appear at 1 730, 1 452 cm-1 respectively. Hence, it has certain significance of applying surface topography characteristics observation, refractive index testing, chemical composition and infrared spectra analysis to separate authentic nephrite gravel and nephrite gravel imitation dyed by organic stuff.
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[1] 王久华.籽料和田玉的特征[J].山东国土资源, 2008, 24(11):60. [2] 谢平辉.和田玉仔料与仿和田玉仔料的肉眼鉴识[J].云南地质, 2008, 27(1):74-77. [3] 李平, 宋波.软玉子料鉴定探讨[J].中国宝玉石, 2009(5):102-103. [4] 李平, 李凌丽.软玉子料的形状规律及其应用[J].岩矿测试, 2008(5):399-400. [5] 申晓萍, 李新岭, 魏薇, 等.仿和田玉籽料的方法及鉴定特征[J].超硬材料工程, 2009, 21(3):58-61. [6] 买买提明·卡地尔, 库扎提·吐松, 买买提阿布拉·买提斯地克.和田籽玉的色皮及其与土壤的关系[J].和田师范专科学校学报, 2009, 28(5):207-208. [7] 李平, 沈崇辉.软玉子料黑皮和褐皮的致色物测试[J].岩矿测试, 2009, 28(2):194-196. [8] 李平, 钱俊峰.子料黄褐皮的成因研究[J].科技通报, 2011, 27(1):120-122. [9] 王濮, 潘兆撸, 翁玲宝.系统矿物学·中册[M].北京:地质出版社, 1984:330. [10] 闻辂.矿物红外光谱学[M].重庆:重庆大学出版社, 1989. [11] 吴瑾光.近代傅里叶变换红外光谱技术及应用[M].北京:科学技术文献出版社, 1994.
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