河南新密密玉的宝石学特征及成因研究

发布时间：2018-01-28 21:38

本文关键词： 密玉石英岩玉宝石学特征结构成因致色机理　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：密玉为石英质玉石,产于河南省密县,现新密市,质地细腻,有红、黄、紫、黑等多种颜色,而绿色鲜艳,更有“河南翠”之称。本文在实地考察后对河南新密的地质环境和密玉矿区的产状进行介绍,对影响密玉形成的因素进行分析,使用常规宝石学仪器及显微硬度计对密玉的宝石学特征进行测试,并采用电子探针、拉曼光谱、X荧光光谱、X射线衍射分析等现代测试技术对密玉的颜色和结构成因进行系统的研究,确定其矿物组成,分析不同颜色密玉的致色机理,为开发利用密玉资源提供理论依据。密玉产出状态为脉状、扁豆状,在助泉寺矿区呈断续分布,矿体为石英岩,地层性质稳定,多呈层状,受褶皱控制,断裂发育,绿色密玉呈脉状赋存于裂隙中。密玉颜色以白色和绿色为主,另有红、紫、黄、黑及数种颜色的混合色调。密玉为玻璃光泽至油脂光泽,半透明至微透明,折射率1.54,相对密度为2.631~2.658,紫外荧光惰性,滤色镜下仅绿色密玉显示暗红色,显微硬度换算成摩氏硬度为:6.4~6.9。密玉的结构主要为花岗变晶结构、微细粒结构,块状构造。XRF分析显示,密玉化学成分的平均含量为SiO2=98.13%,其次为Al2O3=0.67%,Fe2O3=0.24%,K2O=0.18%,CaO=0.16%,MgO=0.06%,Na2O,Ti O2微量。不同颜色密玉的主要成分基本不变,次要化学成分随颜色变化而有所差别。绿色密玉Cr含量较高;黄、红、紫、黑密玉具有较高的Fe含量。通过偏光显微镜观察,并结合电子探针、X射线粉晶衍射、拉曼光谱等大型仪器测试,得出密玉是显晶质石英质玉石,主要矿物为石英,含量在97%以上,次要矿物有绢云母、锆石、电气石、铁质矿物等。绿色密玉中的绿色部分主要为绢云母,位于石英裂隙之间或石英上,黄色密玉中球粒状针铁矿呈黄色,沿石英颗粒间隙分布,红色、黑色密玉中的片状赤铁矿使其色,赤铁矿颗粒薄,则色浅呈红色,颗粒厚者色深,为黑色,紫色密玉中赤铁矿分布,紫色成因与之相关。
[Abstract]:Miyu is quartz jade, produced in Mixian, Henan Province, now Xinmi City, fine texture, red, yellow, purple, black and other colors, and bright green. This paper introduces the geological environment and occurrence of Miyu mining area in Xinmi, Henan Province, and analyzes the factors that affect the formation of Miyu. The gemstone characteristics of Miyu were tested by conventional gemstone apparatus and microhardness tester. The electron probe Raman spectra and X-ray fluorescence spectra were used. X-ray diffraction analysis and other modern testing techniques are used to systematically study the origin of the color and structure of Miyu, to determine its mineral composition and to analyze the chromogenic mechanism of Miyu with different colors. In order to provide theoretical basis for the exploitation and utilization of Miyu resources, the production state of Miyu is vein-like and lentil, which is intermittently distributed in Junquansi mining area, and the orebody is quartzite with stable stratigraphic properties, mostly stratified and controlled by folds. The color of the jade is mainly white and green, and there is a mixture of red, purple, yellow, black and several colors. Miyu is glass-gloss to grease luster. The index of refraction is 1.54, the relative density is 2.631 ~ 2.658, the ultraviolet fluorescence is inert, and only green jade shows dark red in the filter. The microstructure of Miyu is mainly granitic structure, fine grain structure and block structure. XRF analysis shows that the microhardness is: 1. 6. 4 and 6. 9. The microstructure of Miyu is mainly composed of granitic structure, fine grain structure and block structure. The average content of chemical composition of Miyu is 98.13% Sio _ 2, followed by 0.67% Al _ 2O _ 3 and 0.24% K _ 2O _ 3. CaO0.16% MgO0.06 is a trace amount of Na _ 2O _ 2O _ 2 TIO _ 2. The main components of different colors of Miyu are basically unchanged. The secondary chemical composition is different with the change of color. The content of Cr in green Miyu is higher. Yellow, red, purple and black jade have high Fe content. Observed by polarizing microscope, combined with electron probe X-ray powder diffraction, Raman spectroscopy and other large-scale instruments. It is concluded that Miyu is a crystal quartz jade, the main mineral is quartz, the content of which is more than 97%, the secondary minerals are sericite, zircon, tourmaline, iron minerals, etc. The green part of green Miyu is mainly sericite. Located between the quartz fissures or on quartz, the globular goethite in the yellow jade is yellow and distributes along the quartz grain gap. The red and black hematite make it color, the hematite particle is thin, then the color is light red. The color of thick particles is black, purple dense jade hematite distribution, purple origin is related to it.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P619.28

【相似文献】