中文摘要：
天河石是常见的中低档宝石,属微斜长石变种,因独特的绿色、蓝色或者蓝绿色近年来走红珠宝市场。本文采用常规宝石学测试方法和现代大型仪器(扫描电镜、X射线粉晶衍射、电子探针、红外光谱、拉曼光谱、激光剥蚀电感耦合等离子质谱等)相结合,测试分析三个产地天河石样品(中国新疆、莫桑比克、马达加斯加)的常规宝石学特征和矿物学特征。通过X粉晶衍射确定了天河石的矿物组成;通过激光剥蚀电感耦合等离子体技术测定了天河石的主微量元素的含量;通过红外拉曼研究天河石的谱学特征。对三个不同产地天河石样品之间的宝石学矿物学特征进行横向比较,为不同产地天河石样品的产地鉴别提供依据。三个不同产地天河石样品常规宝石学特征区别不大。折射率为1.510~1.530,双折射率为0.007~0.020;相对密度为2.46~2.55,摩氏硬度为6.27~6.75。三个不同产地天河石样品的矿物成分、化学成分基本相同,新疆、莫桑比克天河石样品的微观结构更为致密。不同产地天河石样品的晶胞参数不同,新疆天河石样品的晶胞参数a、b、c、V最大,马达加斯加天河石样品最小。天河石的红外和拉曼峰受Si/Al有序度的影响较大,不同产地天河石图谱差别较大。红外光吸收峰有1140 cm~(-1)、1085 cm~(-1)、1052 cm~(-1)、1018 cm~(-1)、772 cm~(-1)、728 cm~(-1)、650 cm~(-1)、607 cm~(-1)、584 cm~(-1)、537 cm~(-1)、467 cm~(-1)、430 cm~(-1),拉曼吸收峰有1126cm~(-1)、998cm~(-1)、813cm~(-1)、750cm~(-1)、650cm~(-1)、510cm~(-1)、480cm~(-1)、290cm~(-1)、150cm~(-1),红外光谱和拉曼光谱可以将新疆和马达加斯加天河石样品区分开来。天河石的紫外-可见吸收光谱的吸收峰有210nm、250nm、280nm、320nm、380nm、640nm、730nm,和天河石中的微量元素有关。天河石样品含有多种微量元素,颜色和微量元素含量之间存在相关性,推测天河石颜色由混入晶格的微量元素Pb引起。不同产地天河石样品中微量元素含量、紫外-可见吸收光谱不同,可作为产地鉴别的依据。
英文摘要：
Amazonite is a common medium and low grade gemstone,belonging to the variant of microcline,which has become popular in the jewelry market in recent years due to its unique green,blue or blue-green color.This article uses conventional gemological testing methods and modern large-scale instruments(Scanning electron microscopy,X-ray powder diffraction,electron probe,infrared spectroscopy,Raman spectroscopy,laser ablation inductively coupled plasma mass spectrometry(LA-LCP-MS),etc.)to test and analyze the conventional gemological and mineralogical characteristics of amazonite samples of three different origin.Observing the mineral structure of amazonite under Polarized Microscope;Determination of mineral composition of amazonite by XRD;Determination of main and trace elements in amazonite by LA-LCP-MS;Study on the Spectral Features of amazonite by IR and Raman.A lateral comparison of gemological and mineralogical characteristics between amazonite samples of three different origins is carried out,and the results provide basis for the identification of the origin of the amazonite samples.General gemological characteristics have little difference among amazonite from three different origins.The refractive index is 1.510~1.530,the birefringence is1.510~1.530,the relative density is 2.46~2.55,Mohs hardness is 6.27~6.75.The mineral composition and chemical composition of amazonite samples are basically the same,the microstructure of amazonite sample from Xinjiang and Mozambique is more compact.The unit cell parameters of the Xinjiang origin sample are the largest,and the Madagascar origin samples are the smallest.The infrared and Raman peaks of amazonite are greatly affected by the Si/Al ordering degree,and there are great differences in the amazonite samples from different producing areas.Infrared absorption and Raman scattering peak are 1140 cm~(-1)、1085 cm~(-1)、1052cm~(-1)、1018 cm~(-1)、772 cm~(-1)、728 cm~(-1)、650 cm~(-1)、607 cm~(-1)、584 cm~(-1)、537 cm~(-1)、467 cm~(-1)、430 cm~(-1) and 1126cm~(-1)、998cm~(-1)、813cm~(-1)、750cm~(-1)、650cm~(-1)、510cm~(-1)、480cm~(-1)、290cm~(-1)、150cm~(-1).Infrared and Raman spectra can separate Xinjiang and Madagascar amazonite samples.The absorption peaks of UV-Vis absorption spectra of amazonite samples are 210nm,250 nm,280 nm,320 nm,380nm,640 nm,and 730 nm,which are related to trace elements in amazonite.The amazonite samples contain many trace elements,and there is a correlation between the color and trace element content.It is inferred that the color of the amazonite is caused by trace elements Pb mixed into the crystal lattice.The content of trace elements and UV-visible absorption spectra in amazonite samples of different origin are different and the difference can be used as the basis to identify their origins.
