新疆且末天泰矿区和田玉宝石矿物学特征及成因研究

发布时间：2018-10-05 10:04

【摘要】：新疆且末是和田玉最重要的产地之一。本文对新疆且末天泰矿区和田玉进行了宝石矿物学特征、地质成因等方面的研究,为开发利用和田玉资源提供理论依据。重点研究矿物学特征(包括玉石的结构、矿物组成、化学组成、微量元素分布等),调查新疆且末天泰矿区和田玉矿床的地质特征和成因。进行宝石学常规测试得出:该矿区和田玉颜色主要为白色、浅黄-褐-深褐色、浅绿-深绿色,以青白色为主;透明度为微透明;光泽为玻璃光泽至油脂光泽;摩氏硬度6.29左右;相对密度2.96左右;折射率1.60左右。选取典型样品进行磨片,观察和田玉在偏光显微镜、电子显微镜下的微形貌,研究其结构特征,得出:该矿区和田玉的显微结构种类多样,主要为显微纤维变晶结构和毛毡状变晶结构;和田玉的主要构造类型为块状构造。运用电子探针、红外光谱、XRD、拉曼光谱等现代技术研究和田玉矿物成分,得出:该矿区和田玉主要矿物成分为透闪石,杂质矿物主要有透辉石、白云石、榍石、绿帘石、磁铁矿、磷灰石、褐铁矿等。运用化学成分分析等手段研究和田玉化学成分,得出:该矿区和田玉主要化学成分的含量与透闪石的理论成分接近,基本反映了透闪石的主要化学成分Ca2Mg5[Si8O22](OH)2,且样品绿色(青色)越深,Fe元素含量越高。研究和田玉“糖色”的致色机理,得出:糖玉的化学成分中,Fe含量的增加与糖玉的颜色加深无明显关系。铁质矿物浸染分布于糖玉透闪石颗粒间、微裂隙中,致使其呈现黄褐色,推测为针铁矿。通过氧、硅稳定同位分析,稀土元素分析等,得出:该矿区和田玉矿床属于岩浆热液交代型成因矿床,生成于镁质大理岩与中酸性侵入岩的接触交代部位。
[Abstract]:Xinjiang Qianluo is one of the most important places of production of Hetian jade. In this paper, the characteristics of gemstone mineralogy and geological origin of Hetian jade in Qiemuotai mining area, Xinjiang, are studied in order to provide a theoretical basis for the exploitation and utilization of Hetian jade resources. The mineralogical characteristics (including the structure, mineral composition, chemical composition, distribution of trace elements, etc.) of Jade are mainly studied, and the geological characteristics and genesis of Hetian Jade deposit in Qijimuotai mining area, Xinjiang, are investigated. It is found that the color of Hetian jade in this mine is mainly white, yellowish-brown-dark brown, light green and dark green, mainly green and white, transparency is slightly transparent, luster is glass luster to grease luster; The hardness of Morse is about 6.29, the relative density is about 2.96, and the refractive index is about 1.60. Selected typical samples for grinding, observe the micro-morphology of Hetian jade under polarizing microscope and electron microscope, and study its structural characteristics. It is concluded that the microstructure of Hetian jade in this mining area is various. The main structural types of Hetian jade are block structure. The mineral composition of Hetian jade is studied by means of electron probe, infrared spectrum XRD and Raman spectroscopy. It is concluded that the main mineral composition of Hetian jade in this mining area is tremolite, impurity minerals are mainly diopside, dolomite, sphene, verdant, magnetite, etc. Apatite, limonite, etc. The chemical composition of Hetian jade is studied by means of chemical composition analysis. It is concluded that the content of main chemical composition of Hetian jade in this mining area is close to the theoretical composition of tremolite. The main chemical composition of tremolite, Ca2Mg5 [Si8O22] (OH) _ 2, is basically reflected, and the deeper the green (cyan) of the sample is, the higher the content of Fe is. The mechanism of "sugar color" of Hetian jade is studied. It is concluded that the increase of Fe content in the chemical composition of the sugar jade has no obvious relationship with the color deepening of the sugar jade. Iron minerals are disseminated between the grains of sugar jade tremolites and in the microcracks, resulting in yellowish brown, which is supposed to be goethite. Through the analysis of oxygen, silicon stability and rare earth elements, it is concluded that the Hetian jade deposit belongs to magmatic hydrothermal metasomatic type and is formed in the contact metasomatism between magnesia marble and intermediate-acid intrusive rocks.
【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】：2016
【分类号】：P619.28

【相似文献】