充填处理天河石的谱学特征研究

Study on the Spectral Characteristics of Filled Amazonite

采用常规宝石学测试方法,结合能量色散型X射线荧光光谱仪、傅里叶变换红外光谱仪、激光拉曼光谱仪、荧光光谱仪等测试分析方法,对比天然及充填处理天河石的谱学特征,旨在探寻有效无损鉴别充填处理天河石的方法。结果表明,充填处理天河石同天然天河石折射率范围一致,均为1.52~1.53。充填处理天河石的光泽较弱,为弱玻璃—蜡状光泽,有别于天然天河石的玻璃光泽。放大观察,部分充填处理天河石样品可见裂隙处出现明显内凹现象,内凹处光泽明显较弱,裂隙中还可存在气泡。较弱的光泽以及放大观察可以辅助区分天然天河石与充填处理天河石。天然及充填处理天河石中所含的主量元素种类一致,均含有Al,Si,K和Rb,并未检测到属于充填物质的异常化学元素。红外反射光谱在指纹区都表现为天河石本身基团振动所产生的吸收;在官能团区,天然天河石没有明显吸收,而充填处理天河石存在由(—CH—)振动所产生的2844和2912 cm^(-1)两处特征吸收峰。天然及充填处理天河石的激光拉曼光谱在100~1500 cm^(-1)波段内特征相同,均表现为天河石本身基团振动所产生的拉曼峰。充填处理天河石在100~3700 cm^(-1)波段内荧光干扰明显强于天然天河石,当检测到表面裂隙中的有机充填物时荧光干扰会更强并出现区别于天然天河石的拉曼峰。天然天河石与充填处理天河石的三维荧光光谱不管是荧光中心位置还是相对强度都没有典型区别,且天然天河石自身具有不同的荧光特征,三维荧光光谱不能有效区分天然天河石与充填处理天河石。

Using conventional gemological methods,energy dispersive X-ray fluorescence spectrometer,laser Raman spectrometer,Fourier transform infrared spectrometer and fluorescence spectrometer to compare the spectral characteristics of natural and filled amazonite and to explore the effective and non-destructive identification method of filled amazonite.The results showed that the refractive index of filled amazonite is consistent with that of natural amazonite,which is 1.52~1.53.The luster of filledamazonite is weaker glass to wax,which is weaker than natural amazonite.Enlarged observation shows that the surface is concave in the partially filled amazonite samples,and the luster is different from the surrounding.There may be bubbles in the cracks.So the weak luster and magnified observation can help distinguish natural amazonite from filled amazonite.The main elements are the same either in nature or in filled amazonite,including Al,Si,K and Rb.No abnormal chemical elements belonging to the filling material have been detected.The infrared reflection spectrum in the fingerprint area is the absorption of the group vibration of amazonite.In the functional group area,natural amazonite does not absorb obviously,while the filled amazonite has two characteristic absorption peaks that 2844 and 2912 cm^(-1),produced by the vibration of(—CH—).The laser Raman spectra of natural and filled amazonite are the same in the 100~1500 cm^(-1)band,which are all the Raman peaks produced by the group vibration of amazonite.The fluorescence background of filled amazonite in the 100~3700 cm^(-1)band is stronger than natural amazonite.When organic filling material in surface fissures is detected,the fluorescence background will be stronger,and the Raman peaks will appear different from natural amazonite.There is no typical difference between natural and filled amazonite,and natural amazonite different fluorescence characteristics by themselves.The three-dimensional fluorescence spectrum cannot distinguish natural amazonite from filled amazonite.