水晶中金红石的宝石矿物学特征研究

发布时间：2018-10-10 11:21

【摘要】：石英是自然界最常见的矿物,晶莹剔透的宝石级石英——水晶内部通常含有丰富多样的包裹体,这些包裹体使得水晶不仅具有美学价值、收藏及经济价值,也使它成为研究热点。金红石是水晶中常见固体包裹体之一,水晶中金红石颜色丰富,有金色细丝状“金发晶”,棕色“铜发晶”,银白色“钛晶”;形态分布多样,有朝一个方向生长的顺发晶,有金红石呈六个方向的六射“星光发晶”,还有朝多个方向生长的放射状金红石发晶,也有杂乱无序状“乱发晶”;水晶中金红石针粗细长短各不相同,有毛发状,纤维状,细针状,也有2-5mm宽的板状金红石,长度最短肉眼不可见,长着可达10cm。水晶中金红石颜色、大小与其生长环境密切相关,金红石形态和延长方向与金红石最初的形成方式,水晶的生长方向密切相关。本次研究选取了有代表性的标本进行了基础的宝石学测试,原石和薄片显微镜观察,对其定向生长的金红石——黑色赤铁矿包裹体和非定向生长的金红石进行了观察和研究。通过大量原石标本显微镜放大观察和薄片偏反光显微镜观察发现大部分定向生长的金红石针依附黑色核心生长,相邻金红石针夹角呈60°,金红石依附基地生长可成六射“金红石星”,根据后续测试黑色基地为含钛赤铁矿。观察测量标本中金红石针夹角,金红石与核心赤铁矿结晶学关系的关系,通过制作金红石和赤铁矿的晶体结构,查阅文献分析推测金红石受依附核心赤铁矿结晶学方向影响出溶生长夹角呈60°。对水晶及内部固体包裹体进行了电子探针背散射观察和成分分析、X射线粉晶衍射、红外光谱、拉曼测试光谱测,得出本次实验标本中金色,棕色固体针状包裹体为金红石,金红石依附生长的黑色核心为含钛赤铁矿,金红石针中铁含量由核心到末端减少。分析之前的薄片及晶体原石观察和之后的测试数据分析,推测水晶中定向生长的金红石依附赤铁矿型包裹体一般由是核心赤铁矿形成后被水晶包裹,若周围条件合适,此时金红石针随水晶一同生长,金红石针生长方向固定,生长速率受到水晶生长速率的影响,沿着沿水晶C轴方向金红石针更长;少数较小的金红石-钛赤铁矿型包裹体被水晶包裹后不再生长,此时金红石针生长方向与长度与水晶无关。
[Abstract]:Quartz is the most common mineral in nature. The crystal with crystal is usually rich in various inclusions, which make the crystal not only of aesthetic value, collection and economic value. It has also become a research hotspot. Rutile is one of the common solid inclusions in crystal. The rutile in the crystal is rich in color, with golden filament "golden hair crystal", brown "copper hair crystal" and silvery white "titanium crystal". There are six-shot "starlight hair crystals" of rutile in six directions, as well as radial rutile hair crystals in many directions, as well as disorderly "random hair crystals." the rutile needles in the crystals are of different sizes, having hair-like and fibrous shapes. Fine needle-shaped, also have 2-5mm wide plate-shaped rutile, the shortest length invisible to the naked eye, up to 10 cm long. The color and size of rutile in the crystal are closely related to its growth environment. The morphology and extension direction of rutile are closely related to the initial formation mode of rutile and the growth direction of crystal. In this study, the representative specimens were selected for the basic gemmological test. The rutile and thin slice microscope were used to observe and study the rutile-black hematite inclusions and the non-directional growth rutile. It was found that most of the directional growth rutile needles were attached to the black core growth through the microscopic magnification observation of a large number of raw stone specimens and the observation of the thin slice deflecting microscope. The angle of the adjacent rutile needle is 60 掳, and the rutile dependency base can be grown into six rutile stars. According to the subsequent test, the black base is ilmeniferous hematite. The crystal structure of rutile and hematite was prepared by observing the relationship between rutile needle angle and the relationship between rutile and core hematite crystallization. It is inferred from literature analysis that the angle of solution growth of rutile is 60 掳influenced by the direction of dependent core hematite crystallization. The X-ray powder diffraction, infrared spectrum and Raman spectroscopy were used to observe the crystal and its inner solid inclusions. The results showed that the gold and brown needle-like inclusions were rutile. The black core of rutile is titanium-bearing hematite, and the iron content in rutile needle decreases from core to end. By analyzing the observation of thin slice and crystal primitive stone before and after the analysis of test data, it is inferred that the directional growth of rutile in crystal depends on hematite type inclusions, which are usually wrapped by crystal after the formation of core hematite, if the surrounding conditions are suitable, At this time the rutile needle grows with the crystal, the rutile needle grows in a fixed direction, the growth rate is affected by the crystal growth rate, and the rutile needle along the crystal C axis is longer; A few smaller rutile-titanium hematite inclusions do not grow after they are encapsulated by crystals. At this time the growth direction of rutile needles is independent of the length of crystals.
【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】：P619.281

【共引文献】