广西大化石矿物学特征研究

发布时间：2018-03-07 10:08

本文选题：大化石　切入点：石英　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：广西大化石是一种观赏石,产于广西壮族自治区河池市大化瑶族自治县岩滩镇红水河流域。大化石是多种矿物组成的集合体,其主要矿物为石英。本文对大化石的宝石矿物学等方面进行研究,确定其化学成分、矿物组分以及结构特征,并进一步推断其表皮颜色成因,为广西奇石市场上色彩艳丽、造型多样的大化石提供合理的解释依据。广西大化石的表皮颜色主要有两类:黄和红色,此外还有黑色、绿色、浅蓝色等。样品几乎均不透明,呈层状结构。棱角有磨圆,但磨圆度不高。点测其折射率范围在1.53至1.56之间;密度在2.65至2.76g/cm3之间,在紫外光下其发光性弱。通过红外光谱、电子探针和X射线粉晶衍射等测试分析表明,广西大化石的矿物成分主要是石英,此外还有少量的长石、辉石和透闪石等矿物。用盐酸将其表皮溶解,将溶液用化学方法测试,测试结果表明其含有Fe3+、Fe2+和Mn2+。同时还有样品遇酸冒泡,含CO32-。在单偏光下和正交偏光镜下,大化石样品薄片中石英、长石多呈粒状结构,有黑色泥质物呈浸染状夹杂其间;透闪石呈柱状结构和纤维状、束状结构。在扫描电镜下观察大化石样品表面形貌,发现石英、长石多为粒状,粒径约5-10μm;透闪石多呈纤维状和柱状,纤维长约8-15μm,宽约1μm;具有半定向。结合地质概况,推断广西大化石为原岩硅质岩在经过火山喷发和侵入作用后,发生硅化、黄铁矿化、大理岩化等,其碎屑物质被剥蚀,经沉积作用,后又发生了低温弱变质作用,最终形成大化石。目前,广西奇石市场稳步发展,大化石的市场前景很大,对大化石的开发利用由以前粗犷式转型为以文化产业的开发为方向;但对大化石的矿物学特征的研究方面较为缺乏,需要更深入的理论研究,进行系统全面的开发,从而打造大化石发展的产业规模。
[Abstract]:Dahua stone in Guangxi is a kind of ornamental stone, which is produced in Hongshui River Basin, Yantan Town, Dahua Yao Autonomous County, Hechi City, Guangxi Zhuang Autonomous region. The main mineral is quartz. In this paper, the authors studied the gemstone mineralogy of the large fossil, determined its chemical composition, mineral composition and structural characteristics, and further inferred the origin of its epidermal color, which is the brilliant color in the market of Qishi in Guangxi. The large fossils in various shapes provide reasonable basis for explanation. The epidermal colors of Dahua stone in Guangxi are mainly of two types: yellow and red, in addition to black, green, light blue and so on. The samples are almost opaque and have a layered structure. The refractive index ranges from 1.53 to 1.56, the density is between 2.65 and 2.76 g / cm ~ 3, and the luminescence is weak in ultraviolet light. The results of infrared spectroscopy, electron probe and X-ray powder diffraction show that the refractive index is in the range of 1.53 to 1.56, and the density is between 2.65 and 2.76 g / cm ~ 3. The mineral composition of Guangxi Dahua stone is mainly quartz, in addition to a small amount of feldspar, pyroxene and tremolite minerals. The epidermis is dissolved with hydrochloric acid, and the solution is tested by chemical method. The results show that the samples contain Fe3 Fe2 and Mn2, and the samples are acid-bubbling and CO32-.The quartz and feldspar in the thin slice of the large fossil sample are mostly granular in structure under single polarized light and orthogonal polarizer. Tremolites are columnar and fibrous, bunchy. The surface morphology of large fossil samples is observed by scanning electron microscope. It is found that quartz, feldspar is mostly granular, its diameter is about 5-10 渭 m, tremolite is mostly fibrous and columnar. The fiber is about 8-15 渭 m in length and 1 渭 m in width; it is semi-directional. Combined with the geological survey, it is inferred that the detrital material of Dahua stone in Guangxi is denudated after volcanic eruptions and intrusions, such as silicification, pyrite, marble, etc. After sedimentation, the low-temperature weak metamorphism took place and finally formed the big fossils. At present, the market of Qishi in Guangxi is developing steadily, and the market prospect of the big fossils is very great. The development and utilization of large fossils have been transformed from rough to cultural industries, but the study of mineralogical characteristics of large fossils is relatively scarce, so it is necessary to carry out more in-depth theoretical research and systematic and comprehensive development. In order to create a large fossil development of the industrial scale.
【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】：2015
【分类号】：P575

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