具晕彩效应长石的宝石学特征研究

Study on Gemological Characteristics of Iridescent Feldspars

在珠宝市场上常见作为中低档宝石品种的长石因具特殊的晕彩效应而受到消费者的喜爱。文章对具晕彩效应的钠长石和拉长石成品进行了宝石学特征研究分析,对样品进行了常规宝石学测试、红外光谱(FTIR)、拉曼光谱(Raman)和X射线荧光光谱(XRF)等测试。结果表明,样品均具相似外观的晕彩效应,钠长石的折射率(1.53~1.54)较拉长石(1.56)稍低;红外吸收光谱不同的长石在1000cm^-1~1100cm^-1和700cm^-1~800cm^-1两个范围内分裂程度存在差异;拉曼光谱表现均为不同长石族矿物的拉曼位移;成分分析中K,Na和Ca含量在不同长石样品中具明显成分差异。

Feldspar,a kind of middle and low grade gem,is popular in jewelry market as its special halo effect.In this paper,the gemmological characteristics of albite and labradorite stone with halo effect were studied and analyzed.The samples were tested by conventional gemmological tests,FTIR,Raman,and XRF.The results showed that the samples had similar halo color effect;the refractive index of albite(1.53-1.54)was slightly lower than that of labradorite(1.56);the degree of splitting of feldspar with different infrared absorption spectra was different in the range of 1000cm^-1~1100cm^-1 and 700cm^-1-800cm^-1;the Raman spectra showed the Raman displacement of different feldspar minerals;the contents of Ca,K,and Na in different feldspar samples were different.