福建寿山豆耿石的矿物学和谱学初探  

Mineralogy and Spectra Study on Dougeng Stone from Shoushan, Fujian Province

作　　者：席佳鑫 陈涛[1] XI Jia-xin;CHEN Tao(Gemmological Institute,China University of Geosciences(Wuhan),Wuhan 430074,China;Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China)

机构地区：[1]中国地质大学(武汉)珠宝学院,湖北武汉430074 [2]中国科学院广州地球化学研究所,广东广州510640

出　　处：《光谱学与光谱分析》2020年第4期1179-1185,共7页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划(2018YFF0215403);国家自然科学基金项目(41572033);中国地质大学(武汉)珠宝检测技术创新中心开放基金项目(CIGTXM-201805)资助。

摘　　要：运用X射线粉晶衍射、傅里叶红外光谱、拉曼光谱等光谱学方法,辅以静水称重法、扫描电镜、湿化学分析等矿物学测试手段,对近年来在福建寿山发现的寿山石新品种--豆耿石的谱学和矿物学特征进行了研究。XRD测试结果表明样品豆耿石的主要矿物成分是有序度存在差异的地开石;物相和多型分析表明除2M1型地开石外的杂质矿物成分有黄铁矿、明矾石、多型为2M和1Tc过渡结构的叶蜡石和2M1多型的伊利石;对红外光谱谱峰的分析显示与XRD测试结果相符的物相特征,表明样品以无序地开石为主;由于样品切片显微镜下性状表明样品中浸染色脉和不透明矿物的含量对样品外观颜色存在显著的影响,因此使用原位拉曼光谱手段对微区色脉以及不透明矿物进行测试,结果显示光谱谱峰、拉曼位移和拉曼散射峰均表现出典型FeS2光谱特征,说明样品中对豆耿石颜色起重要作用的深色部分主要成分均为黄铁矿;扫描电子显微镜下可见地开石呈显微隐晶一微晶结构,部分样品局部可见深色浸染色脉包裹着显微粒状的黄铁矿,自形-半自形结构分布;结合各化学分析与光谱测试结果分析可知,豆耿石的物理和矿物学性质与其密度、有序度和内部显微形貌的均匀致密程度存在关联;豆耿石的颜色成因与前人研究的寿山黑田(黑色田黄)及坑头黑不同,主要为呈微晶分布(粒度范围3~20μm)的杂质矿物黄铁矿致色,基质地开石中的铁离子对呈色贡献不大。This paper studied main characteristics of Dougeng stone, by means of several Spectra methods like X-ray powder diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and Raman spectra, as well as mineralogical methods like hydrostatic weighing method, scanning electron microscope(SEM) and liquid chemistry analysis. XRD result showed that the main mineral component of Dougeng stone was dickite, and the disintegration degree of the diffraction peaks and the strength of weak spectroscopie k≠3 represented the difference of the order degree of the sample dickite. Phase and polytype analyses showed that apart from dickite with 2 M1 structure, there were also pyrite, alunite, pyrophyllite with a transition structure of 2 M and 1 Tc, and 2 M1 illite. The analysis of the spectroscopies of the infrared spectrum showed that although there were differences in the order degree of samples, they all conformed to the infrared spectral characteristics of disordered dickite, according to peak position change and disintegration degree, which was consistent with the XRD test results. Since the microscopic characteristics of the sample section showed that the contents of the infected dark veins and opaque minerals in the sample had a significant influence on the appearance color of the sample, in-situ Raman spectroscopy was used to test the dark veins and opaque minerals. The results showed that the spectrum position, Raman shift and Raman scattering peak turned out to be typical spectral characteristics of FeS2, which meant that it was pyrite in the sample as the dark component played an important role in the color of Dougeng stones. The scanning electron microscope result revealed that the dickite particles were in microscopic cryptocrystalline-microcrystalline structure, appearing as pseudohexagonal platy, with local pyrite found to be microgranular in automorphic-semiheteromorphic structure in some samples. According to the results of chemical analysis and spectral analysis, the physical and mineralogical properties o

关 键 词：豆耿石 地开石 光谱 矿物成分 颜色成因 

分 类 号：TS93[轻工技术与工程]