一种粉色蛋白石的矿物组成及其命名建议

Mineral Composition and Nomenclature Suggestion of a Type of Pink Opal

本文选取一类含有共生矿物的粉色蛋白石进行测试分析。显微激光拉曼光谱测试表明样品中的主要矿物为蛋白石(含方石英),次要矿物包含坡缕石、石英、斜硅石、碳酸盐矿物等;紫外―可见吸收光谱测试表明样品的颜色与含有机物(如有机醌类)的坡缕石有关;通过放大观察可初步判断样品所含共生矿物的分布状态,其中石英有两种存在形式,一种是以较高透明度的大颗粒单晶石英(或大面积多晶质石英)形式独立分布于蛋白石之中,表面光泽及透明度与主体矿物差异明显,边界清晰,另一种是石英以较小颗粒穿插分布于蛋白石中,表面可见光泽差异,边界较清晰,透明度差异不明显;显微红外光谱测试显示,当石英以较小颗粒穿插分布于蛋白石中时,随着测试范围内石英面积占比的增加,1187 cm−1附近的红外谱峰强度相对于1110 cm−1峰强逐渐增强,且I 1187/I 1110比值与石英面积占比呈现近似线性关系。综合上述研究分析,本文总结出该类蛋白石样品的实验室鉴定方法,并针对该类样品的特征提出了合理的命名建议。

In this study,a type of pink opal containing paragenous minerals was selected for testing and analysis.Micro-Raman spectroscopy showed that the main mineral of the sample is opal(containing cristobalite),and the secondary minerals include palygorskite,quartz,plagioclase,carbonate,etc.UV-Vis spectroscopy revealed that the color of the sample is associated with palygorskite containing organic materials(e.g.,quinone).The distribution state of the paragenous minerals can be preliminarily determined by microscopic inspection.For example,quartz exists in two forms,one is independently distributed in opal as the form of single-crystal quartz with large particles(or polycrystalline quartz with large area)and higher diaphaneity,obvious difference in luster and diaphaneity compared to the main mineral,and clear boundaries;the other form of quartz is interspersed in opal in smaller particles with luster difference,relatively clear boundaries,and subtle diaphaneity difference.The microscopic infrared spectra showed that when quartz is interspersed in opal with smaller grains,the intensity of the infrared peak near 1187 cm-1 increases gradually with the increase of the quartz area share,and the ratio of I 1187/I 1110 shows an approximately linear relationship with the quartz area share.Based on the above research,this paper summarized a laboratory testing method of this kind of opal and proposed a reasonable nomenclature suggestion according to their characteristics.