共查询到19条相似文献，搜索用时 156 毫秒
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易解石-钇易解石族的新变种——钛钇矿 总被引：1，自引：0，他引：1
1970年,某地质队在一富含钇族稀土的中粒白云母化花岗岩中,发现一种黄色板状矿物,经室内研究,确定其为易解石-钇易解石族的一个新变种,定名为钛钇矿。钛钇矿呈良好的结晶体。光性清楚,无需加热即得清晰的X光衍射图谱。这与一般易解石-钇易解石族矿物呈似晶体状态不同。现将其初步研究结果报导于后。 相似文献
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铌铁锐钛矿是含铌、铁的锐钛矿变种。呈土黄色、褐棕色,板状或土粒状。反射率589nm,15.9％,显微硬度H_v=275.9kg/mm~2。计算比重4.4g/cm~3。主要化学成分Nb_2O_534.92—44.3％,TiO_2 29.38—37.58％,Fe_2O_3 14.94—17.19％。化学式:(Ti_(0.44)Nb_(0.31)Fe_(0.25))_(1.00)O_2X射线分析表明该矿物属四方晶系,α=3.828±0.002,c=9.682±0.009,空间群I4_1/amd,Z=4。 共生矿物钕易解石,深红色者变生现象轻微;浅黄色钕易解石与铌铁锐钛矿可能形成于稍晚、较低温度条件下的矿化过程。 相似文献
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安康矿是一种柱红石类新矿物,共化学组成为Ba0.8（Ti,V,Cr）8O16。通讨X光单晶工作。发现其结构在平行c轴方向上,存在一维的不相称超晶格有序。亚结构同柱红石结构,修正的晶胞参数a=10.118（1）A c=2.956（3）A。不相称超结构属四维的布拉维类,可能的超空间群有。不相称超结构与大孔道中的空位、以及由空位引起大阳离子沿c方向上的位移有关 相似文献
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为配合某地含铌矿石工业利用,进行选矿试验研究,作者同田福纯、郭菊兰、路广兰、程五昆等同志,作了矿石物质成分研究,给选矿提供了含铌矿石、易解石矿物特征及其可选性能的资料。一、易解石矿物的特征 相似文献
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Yu. L. Ronkin V. V. Murzin A. Gerdes A. V. Maslov D. V. Varlamov 《Doklady Earth Sciences》2018,478(1):82-87
We have been the first to study in situ the U–Pb isotopic system of aeschynite identified in the gold-bearing magnetite–chlorite–dolomite rocks of the Karabash serpentine massif in the Southern Urals. In the concordia diagram, the U–Pb LA–ICP–MS data on aeschynite are characterized by a considerable discordance, which is consistent with the regression line, the lower crossing of which with the concordia corresponds to an age of 298 ± 18 Ma, whereas the figurative ellipses of coexisting monazite reveal an almost concordant cluster corresponding to the U–Pb age of 317.3 ± 3.3 Ma. It has been established that the closure temperature of the aeschynite system is lower than that of the coexisting monazite. 相似文献
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As well as world class Fe and REE resources the Bayan Obo mineral deposits also hosts significant niobium resources(estimated as 2.2 Mt Nb with an average grade of 0.13 wt% Nb).Niobium in this study is primarily hosted in aeschynite-(Ce) and(Nd),but with subsidiary amounts of pyrochlore,fergusonite-(Ce),fersmite and columbite.Here we report on the paragenetic and textural setting of aeschynite,pyrochlore and fergusonite in the main ore bodies and in a carbonatite dyke.Niobium in a carbonatite sample is hosted in a phase tentatively(due to significant Ca,Mn and Ti contents) identified as fergusonite-(Ce).Aeschynite occurs overgrowing foliation in banded ores,in fractures and vugs in aegirine-rich rocks and in calcite veins.The composition in all settings is similar,but some examples in banded ores develop significant zonation in Y,Th and the REE,inferred to relate to buffering of halogen acid species to low levels by dissolution and fluoritisation of calcite,and the preferential precipitation of LREE from solution due to lower mineral solubility products compared to the HREE.Although lower in total concentration the ratios of REE in pyrochlore are similar to those of aeschynite and suggest the same metal source.The crystallisation of pyrochlore probably relates to growth in paragenetic settings where carbonates had already been eliminated and hence the buffering of F-species activities in the hydrothermal fluid was reduced.Both aeschynite and pyrochlore show evidence of alteration.Primary alteration of aeschynite resulted in leaching of A-site cations(Ca,REE,Th) and Nb,addition of Fe,and ultimately replacement by Ba-Ti phases(baotite and bafertisite).Secondary,metamictisation enhanced,possibly supergene alteration of pyrochlore resulted in hydration,leaching of A-site cations leading to the development of lattice vacancies and increases in Si.The presence of hydrothermal Nb resources at Bayan Obo suggests there may be potential for further Nb discoveries in the area,whilst the trends in element mobility during alteration have significant implications for the utility of A-B oxides as components of materials for immobilisation of radionuclides. 相似文献
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Minor and trace elements in HF-soluble zircons 总被引：2，自引：0，他引：2
Electron probe analysis of a group of HF-soluble zircons from porphyroids of the Thuringian Forest, Germany, established yttrium, phosphorus, and iron to be the significant minor constituents. It is believed that these elements render the zircon structure HF-soluble. The Y content varies from about 6500–48000 ppm=0.83–6.10% Y2O3; the P concentrations range from a low of about 790 to a maximum of 4000 ppm=0.18–0.92% P2O5; the Fe content varies from about 400–15000 ppm=0.06–2.10% Fe2O3. Although both Y and P are distributed throughout each given grain, they are sometimes mutually enriched in growth zones. These zones are also resolved in reflected light micrographs and the electron images. 相似文献
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作者进行了稀土铌钛氢氧化物共沉淀实验,对共沉淀物及其高温灼烧产物进行了XRD、IR、DTA和Raman研究,结合前人高温高压实验结果以及野外地质事实,提出了热液体系复杂氧化物矿物易解石和黑稀金矿的络合物高温水解、氢氧化物共沉淀、脱水去羟、聚合成核和结晶的成因模式。 相似文献
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The Spatial Distribution of Garnets and Pyroxenes in Mantle Peridotites: Pressure-Temperature History of Peridotites from the Kaapvaal Craton 总被引：2，自引：0，他引：2
We present a new method for textural analysis of mineral associationsthat uses digital back-scattered electron and X-ray images obtainedwith the electron microprobe to determine the spatial propertiesof minerals on a two-dimensional surface of the rock at differentscale lengths. We determine modal amounts and average grainsizes of each mineral in the thin section without resortingto ellipsoidal approximations of grain boundaries, and investigatethe spatial relationship of mineral pairs. The method is usedto characterize nine mantle xenoliths exhumed within kimberlitepipes in South Africa and to test whether the pyroxenes arespatially correlated with the garnets. The spatial associationof these minerals is used to develop a model for the evolutionaryhistory of the Kaapvaal peridotites. The observed distributionscan be explained by a two-stage model. In stage 1, harzburgiticresidues are produced by large extents of partial melting atshallow depths ( 相似文献