绿松石及其处理品与仿制品的红外吸收光谱表征

IR Absorption Spectrum Representation of Turquoise,Treated Turquoise and Imitation

采用红外反射光谱技术，对市面上常见的充填和压制处理绿松石、仿绿松石及天然绿松石制品的红外吸收光谱进行了研究和对比。结果表明：充填处理绿松石制品的红外吸收光谱具有由聚合物中‰（CH：）反对称伸缩振动和地（CH2）对称伸缩振动致的吸收谱带（2934-2924，2863-2854cm^-1）及v（C=O）伸缩振动所致的红外吸收特征谱带（1739～1718cm^-1）；仿绿松石制品中则明显缺乏天然绿松石中的v（OH）伸缩振动致红外吸收谱带（3507，3465cm^-1），并出现由vas（CH2）反对称伸缩振动和vs（CH2）对称伸缩振动及v（C=O）伸缩振动致红外吸收谱带以及由各自基团振动的红外吸收特征谱带（指纹区内）。依据这些特征的红外吸收光谱有助于将它们区分开。

By using the infrared reflection spectrum analysis technique, the filled, pressed, imitated and natural turquoises on gem markets are investigated. The results show that the IR peaks at 2 934-2 924, 2 863-2 854 cm^-1 are resulted from the asymmetrical stretching vibration and the symmetrical stretching vibration of CHz and the strectching vibration of v（C=O） peaks lie at 1 739-1 718 cm^-1 in polymer of the treated and imitated turquoises. The imitated truquoises have the characteristic spectra of the asymmetrical stretching vibration and the symmetrical stretching vibration of CH2, and the vibration of v（C - O）and characteristic absorption bands of themselves. But, they lack any typical peaks of stretching vibration of hydroxyl of natural turquoise （3 507, 3 465 cm^-1）. These typical IR spectra play an important role in distinguishing the treated and imitated turquoises from the natural turquoise.