试谈我国东部沿海蓝宝石砂矿地质特征

宝石是重要的非金属矿产之-,本文对我国东部沿海地区新生代玄武岩区蓝宝石砂矿的矿床特征,成矿规律,及其与地质构造之间的关系进行探讨,为寻找宝石矿产提供了-些背景材料。     

山东蓝宝石的呈色机制及改色试验

利用穆斯堡尔谱分析结果以及前人光谱分析等资料，从铁离子的价态入手，重新确立了山东蓝宝石的呈色机制，确定出致蓝因素与致黑因素。认为Fe^2 与Ti^4 对可见光565nm的吸收是使蓝宝石产生美丽蓝色调的原因，而Fe^3 对可见光442nm的吸收是使蓝宝石呈黑色的原因，并在此基础上进行了以消除Fe^3 、保障并增加Fe^2 和Ti^4 为宗旨的改色实验，取得了较好的效果。     

Si^4＋及过渡金属离子在蓝宝石呈色中的作用——数学分析法在离子致色研究中的应用

理想晶体（包括蓝宝石）的颜色与占据其晶格的微量过渡金属元素的种类及含量有直接的关系。玄武岩产状的蓝宝石中含有多种微量元素，这些元素是蓝宝石致色的直接因素。本文通过研究发现，每种微量元素均对可见光的特定波段产生不同程度的吸收，其中，Fe^3 ,Si^4 是使蓝宝石呈现蓝色的主要离子，Cr^3 离子可使蓝宝石呈橙和绿色，Mn^4 离子可使蓝宝石呈黄色，Co^2 离子也可使蓝宝石呈蓝色。本文还做出了蓝宝石中每种微量元素对可见光的特征吸收图即波长－吸收系数图，与分子轨道理论值吻合，把蓝宝石中各离子对可见光的吸收位置和相对吸收强度统一起来。     

中国云南哀牢山含海蓝宝石伟晶岩的起源和成岩模拟实验研究

The Ailaoshan aquamarine-bearing pegmatites are associated with Proterozoic metamorphic rocks in the southern portion of the Ailaoshan fault-folded complex.The gem-bearing pegmatite mineralization zones of the region occur in areas generally consistent with the regional tectonic trend.The pegmatites are found in metamorphic rocks,migmatites and in the inner/outer contact zones of gneissoid granites. The Rb-Sr isochron drawn for the pegmatites is 26～31 Ma,(i.e.in Himalayan).The homogenization temperatures of melt and liquid inclusions in minerals vary from 185 to 920℃,which are comparable to the inclusions observed in banded migmatites and ptygmatic quartz veins in the surrounding metamorphic rocks. The mineralization fluids of the pegmatite were rich in HCO_3 and CO_2,and their compositional assemblages are comparable to metamorphic fluids.Results of H,O,C,Si etc.isotopic analyses and REE,and Be analyses indicates that the sources of mineralization components that formed the pegmatites are closely associated with metamorphic fluids and the enclosing metamorphic rocks. A pegmatite structure simulation experiment was conducted at high temperature and pressure(840℃and 1,500×105Pa.),with various metamorphic rock samples in a water-rich and volatile-rich environment.When the liquidus was reached,the temperature was gradually decreased at the rate of 5～10℃/day over a time period of three months.SEM energy-dispersive spectrum analyses were performed on the experimental products.A series of pegmatoid textures were observed including zonal texture,megacryst texture,drusy cavities,crystal druses,and vesicular texture along with more than ten types of minerals including plagioclase,microcline,quartz and biotite.Different metamorphic rock melts generated different mineral assemblages.Experiment results revealed that the partial melting of metamorphic rocks could form melts similar to pegmatite magmas. Based upon the geological characteristics,geochemistry,and pegmatite texture simulation experimental results,it is concluded that the mineralization components of Ailaoshan aquamarine-bearing pegmatites came from metamorphic rocks.The petrogenetic model for the origin of pegmatites is related to ultrametamorphism and metamorphic anatexis.     

云南海蓝宝石、普通绿宝石与祖母绿

最近十多年来,云南省发现了绿柱石矿物里的5种宝石,即绿色绿宝石、透绿宝石、摩根石、海蓝宝石和祖母绿,其中祖母绿是我国首次发现,填补了我国宝石品种的一项空白。文中对云南省绿柱石类宝石分布的地质特征、宝石学特征和开采、加工与市场状况作了介绍。     

吉林省新生代玄武岩中红、蓝宝石矿找矿方向

通过收集前人资料和野外地质调查及地球化学分析,对中国东部发育红、蓝宝石矿的不同地区进行了对比研究,进而从寄主岩类型、寄主岩形成时代和火山机构四周发育的第四系沉积物特征角度,提出了吉林省应将伊舒带、敦密带、东宁-宽甸带作为首选的红、蓝宝石找矿方向。