近年来绿松石市场上出现了俗称“绿松石伴生矿”的天然矿物, 颜色丰富, 有紫色、 白色、 褐黄色、 黄绿色、 绿色等, 其中黄绿色-绿色系绿松石伴生矿相对其他颜色绿松石伴生矿与绿松石外观较为相似, 鉴别难度较大。 为探究其鉴别特征, 选取两块来自湖北省竹山县市场的黄绿色-绿色系伴生矿原石(样品E和F), 对其进行基础宝石学、 电子探针、 X射线粉晶衍射、 显微激光拉曼光谱及紫外-可见分光光谱测试。 测试结果显示该色系绿松石伴生矿的主要矿物成分为氟磷灰石(Ca5(PO4)3F)、 白云母(KAl2(AlSi3O10)(OH)2)等。 电子探针背散射照片显示样品为结晶颗粒细小的多物相混杂的混合物, 化学成分定量测试结果表明深色物相为含铝的硅酸盐, 而浅色物相为含钙的磷酸盐, 此外两样品含有2.27～6.22 Wt%的CuO和2.43～4.99 Wt%的FeO; 有损测试X射线粉晶衍射可准确测试样品主要矿物为氟磷灰石和白云母及少量绿松石; 样品的氟磷灰石和白云母典型拉曼谱峰可作为有效鉴别依据, 其中964 cm-1附近氟磷灰石的典型拉曼谱峰以及203, 432, 709和3 626 cm-1附近白云母的典型拉曼谱峰可将其与绿松石有效鉴别。 紫外-可见吸收光谱测试结果表明样品的颜色成因与绿松石相似, 主要是由Cu2+和Fe3+的电子跃迁所致。 通过对该色系样品相对较系统的谱学测试, 笔者认为拉曼光谱是鉴别绿松石伴生矿中不同矿物相的无损、 快速、 有效的方法, 氟磷灰石和白云母典型拉曼谱峰可将其与绿松石有效区分。

Recently, there have been many natural minerals commonly known as “turquoise associated minerals”, which are rich in color, such as purple, white, brown, yellow-green, green and so on. However, green-yellow and green turquoise associated minerals have a more similar appearance to other color turquoise associated minerals and are more difficult to identify. In this study, to explore their different features, two green-yellow and green turquoise associated minerals samples (sample E and sample F) were selected from Zhushan County market of Hubei Province. These minerals have been used for the basic gemological test, electron microprobe micro, X-ray powder diffractometer, micro-laser Raman spectrometer as well as Ultraviolet-Visible spectrometer. The test results show that the main mineral components of the associated ores are fluorapatite, muscovite and so on. The results of electron microprobe backscattering photographs show that the associated mineral samples are polyphase mixtures of tiny crystalline particles. And quantitative analysis of the chemical composition of the two phases shows that the dark phase is an aluminium-containing silicate, while the light phase is calcium-containing phosphate. In addition, the samples also contained CuO (2.27%~6.22%) and FeO (2.43%~4.99%), whereas the contents of CuO and FeO in sample F are higher than those in sample E. Furthermore. Damaging test of X-ray powder diffraction can accurately test the main minerals of the samples which are fluorapatite, muscovite and a small amount of turquoise. The typical Raman spectra of fluorapatite near 964 cm-1 and muscovite near 203, 432, 709 and 3 626 cm-1 can be effectively identified from turquoise. The results of ultraviolet-visible absorption spectroscopy show that the color origin of the samples is similar to that of turquoise, mainly due to the electron transition of Cu2+ and Fe3+ ions. Based on the relatively systematic spectroscopic testing of the samples, the authors suggest that Raman spectroscopy is a nondestructive, rapid and effective method for identifying different mineral phases in turquoise associated minerals. The typical Raman peaks of fluorapatite and Muscovite can effectively distinguish them from turquoise.