一种琥珀塑料混合体的鉴别

The identification of a kind of amber-plastic mixture

目前,在检测琥珀样品的过程中,我们发现了一种琥珀与塑料混合在一起的样品,与波罗的海琥珀尤其是蜜蜡非常相像。送检的琥珀塑料混合体样品主要为抛光或者亚光的圆珠散珠或圆珠手串,颜色为黄色或黄白交加,透明至不透明,树脂光泽。本文采用常规宝石学测试手段、红外光谱、拉曼光谱等方法对其进行了研究。结果表明,该样品为琥珀与塑料的混合体,其中黄色部分为波罗的海琥珀,白色部分为醇酸树脂。该琥珀塑料混合体的鉴别特征如下:黄色、白色部分有些界限截然,有些界限不明;黄色部分常见特征的回旋纹,高倍镜下观察常见密集的微小气泡群,折射率为1.54,紫外灯下具有黄绿色的荧光,红外光谱具有2 927、1737、1451、1380、1257、1159、983 cm^(-1)吸收峰,拉曼光谱具有1655、1453 cm^(-1)拉曼峰;白色塑料部分生硬呆板,放大观察常见大个气泡散布,折射率为1.60,紫外灯下具有蓝色的荧光,红外光谱具有3061、1728、1600、1580、1493、1453、1282、1123、1067、745、701 cm^(-1)吸收峰,拉曼光谱具有1735、1607、1460、1048、1011 cm^(-1)拉曼峰。

A kind of mixture of amber and plastic resembling Baltic amber or 'Mila' was recently detected by the authors in the course of testing amber samples.The samples of amber-plastic mixture are yellow or yellow-white in color,vary from transparent to opaque and occur as polished or inferior smooth round beads or hand strings with resinous luster.The samples were studied by using such means as gemological methods,infrared spectrum and Roman spectrum.The results show that these samples belong to the community of amber and plastic,with the yellow part being Baltic amber and the white part being artificial alkyl resins.The characteristics for identifying amber-plastic mixture are as follows:there are obvious boundaries between the yellow part and the white part in some samples,but without obvious boundaries in some other samples.The yellow part is characterized by convoluted lines,dense tiny bubbles group under high-power microscope,refractive index of 1.54,yellow green fluorescence under ultraviolet light,diagnostic infrared absorption spectra such as 2927,1737,1451,1380,1257,1159 and 983 cm^(-1),and Roman spectra such as 1655 and 1453 cm^(-1);the white part is characterized by dull appearance,blue fluorescence under ultraviolet light,the refractive index of 1.60,blue fluorescence under ultraviolet,diagnostic infrared absorption spectra such as 3061,1728,1600,1580,1493,1453,1282,1123,1067,745 and 701 cm^(-1),and Roman spectra such as 735,1607,1460,1048 and 1011 cm^(-1).