利用X射线衍射测定单斜辉石中硬玉组分含量     

王文正  韩宗珠  安英杰 《海洋湖沼通报》1993,(4):45-48

硬玉是单斜辉石中十分重要的端元组分,是单斜辉石分类的主要基础。利用x射线衍射分析确定的硬玉组分含量计算式为Jd(％)=[A-2.235]×25.741,其中Jd为硬玉组分百分含量,A为2—Theta角为30°(d=2.97)时峰值的相对强度Ⅰ与半高宽的乘积,其计算误差仅6.32％。  相似文献   

“硅化”不是“树化”“化石”不能称“化玉”对“树化玉”名词的商榷     

孟祥振  赵梅芳 《上海国土资源》2008,(1):69-70

硅化木,又称树化石、木化石,无论它的内在品质多么优良,依然是“化石”身份,不能把优质硅化木称为“树化玉”。因为按照所谓“化”的含义,“树化玉”就只能解释为“玉”变成了“树”,或解释为“玉”具有了“树”的一些性质和特征,这显然是不对的。再如,古生物化石也不能称为“古生物化玉”。所以将硅化木称“树化玉”是欠妥的。  相似文献   

硬玉的差热分析和紫外荧光光谱研究   总被引：2，自引：0，他引：2  

彭卓伦  彭明生  徐庆鸿 《矿产与地质》2003,17(5):630-631,635

通过对缅甸硬玉的差热分析和紫外荧光光谱研究，发现不同颜色硬玉的紫外荧光谱中的617nm处的谱峰，可能是Cr引起的；对不同颜色硬玉进行的差热分析表明，其熔融温度略有不同，说明其生长环境有一定差异，而硬玉也可能是较好的耐热材料，具一定的开发潜能。  相似文献   

人工合成宝石级翡翠的研究   总被引：4，自引：0，他引：4  

朱成明  金志升 《矿物学报》1997,17(3):245-249

本文以对化学试剂为原料，用静奇谈怪论同温高压固相转变法合成宝石级翡翠的机理和工艺条件进行了实验研究，测定了与硬玉化学组分相同的玻璃物质的高压熔融曲线和固相转变的区域，提出了在熔融曲线左侧附近固相区生长优质硬玉的观点，以及在宝石级悲翠合成中的若干技术问题。  相似文献   

安徽双河含柯石英硬玉石英岩中流体包裹体的研究   总被引：14，自引：1，他引：14       下载免费PDF全文

韩郁菁  张泽明 《地球科学》1997,22(3):322-326

在安徽双河含柯石英石玉石英岩中已识别出５类流体懈裹体，其中早期退变质阶段捕获的包裹体是均一温度低、含盐度较高的水溶包裹体，晚期捕获提均一温度较高、含盐底低的水溶流体包裹体，更晚期的是三相富含ＣＯ２包裹体及均一温度高的气－液两相富Ｃ炮裹体，为限定硬玉石英岩的隆升轨迹提供重要依据，在单相气体包裹体和三相富含Ｃ炮裹体中的气相成分为ＣＯ２和Ｎ２，氮可能来自外部或玉石英岩的原岩。  相似文献   

均匀色空间中绿色翡翠的色差   总被引：7，自引：0，他引：7  

郭颖  范静媛 《岩石矿物学杂志》2004,23(1):65-68

采用MPV-Ⅲ型显微光度计测定了32个翡翠样品的可见光吸收光谱，计算了部分样品的三刺激值。在此基础上引入色度学中均匀色空间及色差的概念，通过计算样品NBS值定量分析了不同翡翠样品间的绿色差异。结果表明，色差的定量计算可以反映样品间的真实颜色差别，并且不同于同色异谱指数，可作为绿色翡翠颜色鉴别中一种较为有效的定量方法。  相似文献   

危地马拉翡翠宝石矿物学特征及其与缅甸翡翠的对比研究     

邢碧倩  施光海  张锦洪  龙楚  张昱  何立言  胡汝杰 《现代地质》2021,35(6):1769-1788

危地马拉目前已成为仅次于缅甸的第二大翡翠原料供应地。这两个产地翡翠辨别的需求愈发迫切,且应用意义较大。采用显微镜观察、电子探针分析及背散射电子照相获得危地马拉蓝水料翡翠的矿物成分及结构构造特征,结合两产地翡翠产出的大地构造环境、自然地理环境、原石特征与矿物成分特征等进行对比分析。总体上,危地马拉翡翠次生原石有一定的磨圆,呈次棱角状,“皮”(风化皮)厚度较薄,较少出现翻砂现象,由“皮”向里,极少甚至几乎不存在“红雾”。相对地,缅甸翡翠次生原石发育显著的球状风化,原石通常有较好的磨圆度,棱角状不明显,“皮”厚度可达数厘米,用手压磨有显著的翻砂现象, “皮”“肉”之间偶可见“红雾”。硬玉与绿辉石成分判别图显示危地马拉翡翠中硬玉和绿辉石呈相对富Ca、贫Na的特征,而缅甸翡翠中硬玉和绿辉石整体呈相对贫Ca、富Na的特征。在Fe含量上,危地马拉翡翠中硬玉的Fe含量较缅甸翡翠中硬玉的Fe含量偏低,而危地马拉翡翠中绿辉石的Fe含量较缅甸翡翠中绿辉石的Fe含量偏高。对翡翠外观特征的充分对比和对判别图的综合分析可应用于实际中翡翠产地的区分。  相似文献   

甘肃“马衔山玉”的宝石学特征研究          下载免费PDF全文

王蕾蕾  邵小鹏  魏学平  窦仕臻 《甘肃地质》2021,(1):84-89

“马衔山玉”是近几年甘肃玉石市场上时常出现的一种玉石品种,由于数量少且价格昂贵。采用常规宝石学仪器测试、偏光显微镜薄片观察、红外光谱仪等测试方法进行测试,结果表明,“马衔山玉”的主要组成矿物为透闪石,次要矿物主要为透辉石。马衔山软玉颜色多为青绿、黄绿色且籽料常见灰白色伴有“水草花”杂质的石皮。马衔山软玉透闪石颗粒细小,主要呈纤维交织结构,质地较新疆软玉稍差,油润度较青海、俄罗斯软玉强。  相似文献   

Jadeitites, albitites and related rocks from the Motagua Fault Zone, Guatemala   总被引：12，自引：0，他引：12  

G. E. HARLOW 《Journal of Metamorphic Geology》1994,12(1):49-68

Jadeitites from Guatemala are found as weathered blocks in tectonized serpentinite in a 15-km zone north of the Motagua Fault Zone. Rock types found with jadeitite include albitites, albite-mica rocks, omphacite/taramitic amphibole-bearing metabasites, chlorite-actinolite schists, talc-carbonate rocks and antigorite schists. In addition to the predominant jadeitic (Jd₉₃_₁₀₀) pyroxene, common phases in jadeitite include micas (paragonite and/or phengite ± rarer phlogopite), omphacite, albite, titanite /Pm zircon, apatite and graphite. Conditions of jadeitite formation are 100-400d? C, 5-11 kbar with 0.0 > log₁₀a_sio2≥= 0.7. Fluid inclusions, coarse textures, vein structures, and rhythmic zoning of pyroxene indicate an aqueuos fluid was involved. Jadeitites are either (1) metasomatic modifications of former felsic-to-pelitic inclusions that have undergone silica depletion plus efficient soda exchange and enrichment, or (2) solution precipitations derived from such a source. The close spatial relationship of faults and shear zones, serpentinites, and jadeitites suggests jadeitites form in a relatively high-P/T setting with substantial flow of sodic fluid in a tectonized zone. Most Guatemalan jadeitites are extensively altered to analcime, albite, taramitic amphibole, (clino)zoisite ± nepheline and preiswerkite. This alteration reflects depressurization /Pm heating to below the jadeite + fluid = analcime reaction at high a_Na. With progressive alteration, analcime and nepheline are replaced by albite; the increase in silica content may result from fluid flowing up a tectonized zone reaching saturation with an albite assemblage. Albitite phases, albite, actinolite, zoisite, /Pm chlorite, phengite, K-feldspar and quartz, record conditions of c. 3-8 kbar at T < 400d? C, indicating a clockwise P-T trajectory of the blocks. Barium aluminosilicates—banalsite, celsian, cymrite and hyalophane—are common minor late-stage phases in jadeitites and albite-rich rocks. Barian phengite is common in albite-mica rocks.  相似文献   

Mode of occurrence and significance of jadeite in the Kamuikotan metamorphic rocks, Hokkaido, Japan   总被引：3，自引：0，他引：3  

MASASHI TAKAYAMA 《Journal of Metamorphic Geology》1986,4(4):445-454

Abstract In the Kamuikotan zone, jadeite occurs in pelitic rocks, in metaplagiogranites, in veins in amphibolites and mafic sedimentary rocks, and in jadeite-albite rocks. In the first and second types, jadeite is associated with quartz, and is often in direct contact with it. However, such rock-types never occur as part of the coherent metamorphic sequence, but are found only as exotic blocks enclosed in serpentinite. Thus, jadeite + quartz-bearing assemblages are not regarded as representative of the Kamuikotan metamorphism. Lawsonite and aragonite, however, commonly do occur in the Kamuikotan metamorphic rocks, and this metamorphism belongs to a subfacies of the lawsonite-albite facies, in which aragonite is stable. The serpentinite matrix which carried jadeite + quartz-bearing pelites and metaplagiogranites into the metamorphic sequence is interpreted as a tectonic rather than a sedimentary melange.  相似文献