绿色低型锆石宝石学特征研究

Gemmological Characteristics of Green Low Type Zircon

对市场上出现的一种绿色宝石(客户声称为绿锆),采用常规宝石学测试以及傅里叶变换红外光谱、紫外-可见吸收光谱、X射线荧光光谱分析等测试方法对其进行初步研究。结果表明,这种绿色宝石为低型锆石,折射率>1.78,比重3.97~4.09,正交偏光下可见异常消光,放大观察可见平直或角状生长纹理,絮状、丝状包体,指纹状包体等,双折射现象不明显。红外光谱指纹区显示在1100~800cm^-1间表现为宏大宽带,没有分裂峰,十分接近玻璃态的红外光谱图。紫外-可见吸收光谱具653.5nm为中心的宽吸收带。X射线荧光光谱仪分析,样品含有硅(Si)、锆(Zr)、稀土元素铪(Hf)、放射性元素铀(U)等。

In order to identify the green gemstones which was named as green zircon in the market,a group of green gemstones were collected and studied by conventional gemmological methods,Fourier transform infrared spectrometer,ultraviolet-visible spectrophotmeter(UV-VIS)and X-ray fluorescence spectrometer(XRF).The results showed that the green gemstones werethe low type zircon with a refractive index less than 1.78 and a specific gravity of3.97~4.09.Abnormal extinction appeared under orthogonal polarization,and the straight or angular growth texture,flocculent,filamentous inclusions,fingerprint-like inclusions were observed by magnification although the bi-refringence phenomenon was not obvious.The infrared spectrum showed a large broadband in the range of 1100~800cm^-1,with no splitting peak,which was almost similar to the glassy spectrum.The ultraviolet-visible absorption spectrum had a 653.5nm wide absorption band.X-ray fluorescence spectrometer analysis showed that the sample contained Si,Zr,rare earth element Hf,and radioactive element U.