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1.
用强功率四圆单晶衍射仪精确地修正了氟碳铈矿和氟铈矿的晶体结构．氟碳铈矿（ｂａｓｔｎａｅｓｉｔｅ，Ｃｅ（ＣＯ３）Ｆ）属六方晶系，其晶胞参数为：ａ＝０．７１４３８（９）ｎｍ，ｃ＝０．９８０８（２）ｎｍ，γ＝１２０°，Ｚ＝６，空间群Ｐ６－２ｃ．使用３６７个（Ｆ≥３σ（Ｆ））独立衍射点，经多轮最小二乘法修正后，最终获得偏离因子Ｒ＝０．０４９９．氟碳铈矿的晶体结构特征表现为［ＣＯ３］平面三角形平行ｃ轴分布，铈的配位数为９，Ｃｅ－Ｏ（Ｆ）平均键长为０．２５１５ｎｍ，Ｃ－Ｏ平均键长０．１３２７ｎｍ，每个氟原子与周围三个铈原子相连．氟铈矿（ｆｌｕｏｃｅｒｉｔｅ，ＣｅＦ３）属六方晶系，其晶胞参数为：ａ＝０．７１４１２（２１）ｎｍ，ｃ＝０．７２９８９（２１）ｎｍ，γ＝１２０°，Ｚ＝６．其空间群为：Ｐ３－ｃ１（Ｎｏ．１６５）．使用３２１个（Ｆ≥３σ（Ｆ）））独立衍射点，经多轮最小二乘法修正后，最终获得偏离因子Ｒ＝０．０５４２．氟铈矿的晶体结构表现为每个氟原子与周围三个铈原子相连接，每个铈原子与周围９个氟原子相连，铈的配位数为９，Ｃｅ－Ｆ平均键长为０．２４６８ｎｍ． 相似文献
2.
对于氟碳钡铈矿（Cordylite—Ce）成分与结构的质疑 总被引：2，自引：0，他引：2
本文讨论了氟碳钡铈矿的成分和结构问题。发现氟碳钡铈矿的成分、密度、折射率三者间的一致性参数很差,晶体结构与光性和空间群相矛盾,单个大阳离子的平均占有体积远大于同类矿物的平均占有体积,它的晶体结构与同类矿物不可类比。由于受当时条件的限制,在以往有关氟碳钡铈矿的成分和结构的资料中存在着一些明显的错误,有必要对其进行重新定义。其结构化学式应改为:(Na_(1-x),Ca_(0·5x))BaCe_2(CO_3)_4F。 相似文献
3.
N. G. Konopleva G. Yu. Ivanyuk Ya. A. Pakhomovsky V. N. Yakovenchuk Yu. A. Mikhailova 《Geology of Ore Deposits》2017,59(8):729-737
Data on the occurrence, morphology, anatomy, composition, and formation conditions of loparite-(Ce) in the Khibiny alkaline pluton are given. Loparite-(Ce), (Na,Ce,Sr)(Ce,Th)(Ti,Nb)2O6, resulted from metasomatic alteration and assimilation of metamorphic host rocks at the contact with foyaite as well as foyaite on the contact with foidolite. This alteration was the highest in pegmatite, and albitite developed there. A decrease in temperature resulted in enrichment of the perovskite and tausonite endmembers in loparite-(Ce) owing to a decrease in the loparite and lueshite endmembers. La and Ce sharply predominate among rare earth elements in the composition of loparite-(Ce). 相似文献
4.
新矿物丁道衡矿-（Ce）：珀硅钛铈矿的同质多象体和硅钛铈矿亚族C（1）位上的钛类似矿物 总被引：1，自引：1，他引：0
丁道衡矿-(Ce):(Ce,La)4Fe2 (Ti,Fe2 ,Mg,Fe3 )2Ti2Si4O22,理想的结构化学式Ce2Ce2Fe2 Ti2Ti2Si4O22单斜晶系,α=1.34656(15)nm,b=0.57356(6)nm,c=1.10977(12)nm,β=100.636(2)°,V=0.84239(46)nm3,空间群P21/a(假C2/m),Z=2.作为硅钛铈矿(chevkinite)族矿物的新成员,它产于举世闻名的白云鄂博铁.稀土.铌矿床镁夕卡岩中,多数单晶体长0.2～1.0 cm,最大者长大于1.5 cm.共生矿物有透辉石、透闪石、钠透闪石、褐帘石-(Ce)、磁铁矿、尖晶石、烧绿石、氟金云母、氟磷灰石、石英和萤石等.矿物具有褐色条痕和半金属一金属光泽的黑色,其褐黑色碎片半透明.性脆、具有贝壳状断口、无解理和裂开.显微硬度(VHN25g)为606.0～717.4 kg/mm/12(相当于摩氏硬度约5.9).矿物实测密度4.83(7)g/cm3,计算密度值4.88(0)g/cm3.丁道衡矿-(ce)的反射色为带灰色的浅黄色,多色性为不同色调的灰色.平均反射率(λ=589nm)为11.4%～12.5%.矿物为二轴晶负光性.作过结构精测的丁道衡矿-(Ce)晶体的电子探针测值:SiO2:19.29,TiO2:18.26,A12O3:0.04,FeO:8.49,Fe2O3,:1.67,ThO2:0.16,MgO:1.32,CaO:2.17,Nb2O5:0.47,Ta2O5:0.00,La2O3:19.53,Ce2O3:28.08,Y2O3:0.00,Na1O:0.01,总量99.46%;其中Fe3 /Fe2 的比值依穆斯堡尔谱换算.根据结构精测每个单位分子式中O=22和C(1)位上Ti优先占位,计算的矿物晶体化学式为(Ce2.13,La1.49Ca0.48Th0 01)Σ4.11Fe2 (Tin0.88Fe2 0.47Mg0.41 Fe0.0)Σ2.03(Ti1.96Nb0 04)Σ2.00(Si2O7)2O3.分别用P21/a和C2/m对丁道衡矿-(Ce)的晶体结构作了精测.结果表明,丁道衡矿-(Ce)的真空间群是P20/a.换言之,它才是真正珀硅钛铈矿[perrierite-(Ce)]的同质多象体.显而易见,硅钛铈矿族矿物既可以有P21/a空间群,又可以有C2/m空间群. 相似文献
5.
Baiyuneboite-(Ce) occurs in the REE-Fe-Nb ore deposits at Baiyunebo, Inner Mongolia. As a new mineral—NaBaCe2[Fl(C034], it is a Na-Ba-REE(Ce-series) fluor-carbonate. The authors have conducted extensive investigations into the basic mineralogy,
mineralogical spectroscopy and X-ray crystallography of the mineral and have elaborately determined its chemical composition.
Numerous data on mineralogical experiments and fundamental parameters with respect to its crystal structure have been obtained.
X-ray structural analyses were elaborated. In addition, high-resolution electron microscopic studies were performed and its
structural image was photographed in order to validate the results of X-ray structural analyses. The experimental data available
in conjunction with the comparison between baiyuneboite-(Ce) and its analogues are sufficiently sensitive to show that baiyuneboite-(Ce)
is a new mineral. 相似文献
6.
7.
本文用强功率四圆单晶衍射仪精确地修正了独居石和磷钇矿的晶体结构。独居石［Ｍｏｎａｚｉｔｅ－（Ｃｅ），ＣｅＰＯ４］属单斜晶系，ａ＝６．７８４３（１７），ｂ＝６．９８９１（１２），ｃ＝６．４５９２（１０），β＝１０３．６２６（１６）°，Ｚ＝４，空间群为Ｐ２１／ｎ。使用１１０６个［Ｆ≥３σ（Ｆ）］的独立衍射点，经多轮最小二乘法修正后，最终获得偏离因子Ｒ＝０．０６０。独居石的结构由孤立的［ＰＯ４］四面体构成，Ｃｅ位于［ＰＯ４］四面体包围之中，Ｃｅ的配位数为９，独居石的Ｃｅ—Ｏ平均键长为２．５５２，Ｐ—Ｏ平均键长为１．５２８。磷钇矿（Ｘｅｎｏｔｉｍｅ，ＹＰＯ４）属四方晶系，其晶格常数为：ａ＝６．８７９１（２４），ｃ＝６．０１４７（１９），Ｚ＝４，空间群为Ｉ４Ｉ／ａｍｄ（Ｎｏ．１４１）。使用１４２个［Ｆ≥３σ（Ｆ）］的独立衍射点，经多轮最小二乘法修正后，最终获得偏离因子Ｒ为０．０４８３。磷和氧形成四面体配位，其Ｐ—Ｏ平均键长为１．５４３；稀土钇与氧原子相连构成八次配位，其Ｙ—Ｏ平均键长为２．３３３。 相似文献
8.
新矿物氟铈硅磷灰石产自加拿大魁北京省的ＭｏｎｔＳｔ．Ｈｉｌａｉｒｅ地区，赋存于霞石正长岩、大理岩捕虏体，方钠石正长岩捕虏体和伟晶岩岩墙中。 相似文献
9.
Summary Within the Nkombwa Hill carbonatite complex, bastnäsite-(Ce), (Ce,La)CO3F, has been identified as an abundant mineral in xenoliths hosted by late-stage ferrocarbonatite sills and dykes. Bastnäsite-(Ce) occurs as fibrous yellow crystals, about 1 µm in size, replacing monazite and in association with baryte, in a matrix of dolomite. In common with bastnäsite-(Ce) from other locations, the bastnäsite-(Ce) of Nkombwa Hill contains up to 70% RE2O3, almost entirely as light rare-earth oxides. However, Nkombwa Hill bastnäsite-(Ce) is relatively deficient in La and enriched in Pr and Nd.
Bastnäsit-(Ce) im Nkombwa Hill Karbonatit-Komplex, Isoka-Distrikt, Nordost-Sambia
Zusammenfassung Im Karbonatit-Komplex von Nkombwa Hill kommt Bastnäsit-(Ce), (Ce-La) CO3F, als eine weitverbreitete Komponente in Xenolithen in späten Ferrokarbonatit-Lagergängen und Gängen vor. Bastnäsit-(Ce) bildet faserige gelbe Kristalle in einer Matrix aus Dolomit, die ungefähr 1 µm groß sind, Monazit verdrängen und mit Baryt assoziiert sind. Ähnlich wie Bastnäsit von anderen Lokalitäten, enthält auch dieser bis zu 70% RE2O3 fast ausschließlich als Oxide der Leichten Seltenen Erden. Der Bastnäsite-(Ce) von Nkombwa Hill ist jedoch relativ verarmt an La und an Pr und Nd angereichert.相似文献
10.
11.
Mihoko Hoshino Mitsuyoshi Kimata Norimasa Nishida Masahiro Shimizu 《Physics and Chemistry of Minerals》2008,35(2):59-70
Dissakisites from Trimouns dolomite mine, France, have two kinds of single crystals: chemical-zoned and homogeneous types.
Back-scattered electron microprobe (BSE) images of these dissakisites reveal both Ca–Al rich dark zones and Fe-ΣREE rich bright
zones. Crystal structures of three dark and two bright zones in a chemical-zoned dissakisite and of a homogeneous zone in
unzoned dissakisite were refined to individual R indices (about 3.0–5.0%) based on 1,400 observed [|F
0| > 4σF
0] reflections measured with MoKα X-radiation using the single crystal diffractometer. The differences in brightness between
their BSE images arise from those in coupled substitutions of the elements occupying A2 and M3 sites. The main reason for
these differences is that ten-coordinated A2 polyhedra and M3 octahedra are directly linked through their shared edge, which
creates a great potential for making this coupled substitution. This zoning indicates that formation of the whole zoned crystal,
where each zone could be grown steadily with its crystallographic axes mutually parallel to each other, may be identified
as autoepitaxy. 相似文献
12.
（Sm，Ce）／Zr基柱撑蒙脱石的微结构特征 总被引：2，自引：0，他引：2
室温条件下，在锆基的基础上加入其他金属离子配制了(Sm，Ce)／Zr基柱化剂。用该聚合阳离子柱撑钙基蒙脱石，室温下d001值为2．1～2．3m，焙烧300℃后，d001值为1．8nm，衍射峰敏锐对称，说明柱撑蒙脱石的热稳定性超过300℃。FTIR分析结果表明(Sm，Ce)／Zr基柱化剂和蒙脱石的Si—O四面体层形成了稳定的[Si—O]—[H(O)-Zr(Sm，Ce)]键，从结构上鳃释了(Sm，Ce)／Zr基柱撑蒙脱石材料结构稳定的机理。 相似文献
13.
14.
Dr. L. C. Hsu 《Mineralogy and Petrology》1992,47(1):87-101
Summary Bastnaesites of Ce and La and their OH-analogs were synthesized and their stability relations were determined atPf = 1 kbar andT = 400 to 900°C in a part of the system (Ce,La)-F-H-C-0. The initial fluid compositions were such that
and HF/(HF + H2O) ratios were 0 to 0.172. XRD and IR studies indicate that bastnaesites equilibrated in initial fluids low in HF are all F-enriched. The hydroxylbastnaesite-(La) is stable up to 810°C and the fluorbastnaesite-(La) is stable up to 860°C. Their condensed breakdown products are La2O2CO3 and LaOF, respectively. The stability of Ce bastnaesites is slightly
dependent. The hydroxylbastnaesite-(Ce) is stable up to 660°C at the
defined by the IQF buffer and up to 640°C by the MH buffer. The fluorbastnaesite-(Ce) is stable up to 800°C at the
defined by the IQF and up to 760°C by the MH buffer. The condensed breakdown product for the hydroxyl end-member is simply CeO2 but for the fluorine one is a combination of CeO2, CeF3, and CeOF. Factors, such as OH vs F,
, and bulk composition, that affect the stability of individual species are discussed. Petrogenic implications resulting from the present study include that bastnaesites can be stable from hydrothermal to magmatic conditions, that F-enriched species can form in an environment relatively low in F content, and that OH-species are rare and occur only in low-temperature environments essentially devoid of F.
With 8 Figures 相似文献
Synthese und Stabilität von Bastndsil in einem Teil des Systems (Ce,La)-F-H-C-O
Zusammenfassung Ce- und La-Bastnäsite, sowie deren OH-Analoga wurden synthetisiert und ihre Stabilitätsbeziehunger beiP f = 1 kbar undT = 400 bis 900°C wurden im System (Ce,La)F-H-C-O bestimmt. Die anfänglichen Flüssigkeitszusammensetzungen waren so, daß und die HF/(HF + H2O)-Verhältnisse 0–0.172 waren. Röntgenpulver- und Ultrarot-Untersuchungen zeigten, daß Bastnäsite, die mit anfänglich HF-armen Flüssigkeiten equilibriert wurden, alle an F angereichert sind. Hydroxilbastndsit-(La) ist bis 810°C und Fluorbastnäsit-(La) bis 860°C stabil. Ihre festen Zersetzungsprodukte sind La2O2O3, bzw. LaOF. Die Stabilität der Ce-Bastnäsite hängt etwas von ab. Hydroxilbastnäsit-(Ce) ist bei des Eisen-Quarz-Fayalit-Puffers bis 660°C stabil und mit Magnetit-Hämatit-Puffer bis 640°C. Das feste Zerfallsprodukt ist für das Hydroxil-Glied nur CeO2, für das Fluor-Glied eine Mischung aus CeO2, CeF3 und CeOF. Faktoren, welche die Stabilität der einzelnen Spezies beeinflussen, werden diskutiert, wie das Verhältnis OH zu F, und die Gesamtzusammensetzung. Petrogenetische Folgerungen aus der vorliegenden Studie schließen ein, daß Bastnäsite von hydrothermalen bis zu magmatischen Bedingungen stabil sein können, daß sich an F angereicherte Glieder in relativ F-armer Umgebung bilden können, und daß OH-Glieder selten sind und nur unter Bildungsbedingungen niedriger Temperatur und weitgehender Abwesenheit von F auftreten.
With 8 Figures 相似文献
15.
Paleoproterozoic kimberlite from the Kimozero area in Karelia is the oldest rock of this type in Russia. It is strongly tectonized, metamorphosed, and it finally transformed into metakimberlite of the prehnite-pumpellyite facies with widespread lanthanide minerals: allanite-(Ce), bastnaesite-(Ce), bastnaesite-(La), parisite-(Ce), and monazite-(Ce). The contacts between their crystals and other metamorphic minerals, e.g., titanite, antigorite, and tremolite, are characterized by induction surfaces of concerted growth. Among lanthanide minerals, allanite-(Ce) is the most abundant. It occurs close to clinochlore pseudomorphs after phlogopite or as intergrowths with titanite in aggregates of tremolite–actinolite, calcite, and dolomite. Allanite crystals from the Kimozero area are not zonal, but vary in lanthanide contents and the Fe3+/Fe2+ ratio in grains no more than tens of microns from one another. Kimozero allanite mostly belongs to the allanite–ferriallanite series (up to 30% of ferriallanite endmember); the lesser amount corresponds to the allanite–Cr-bearing allanite series. At the late stage of metamorphism, allanite was partly replaced with parisite, bastnaesite, or monazite. 相似文献
16.
Baiyuneboite-(Ce) is a new fluor-carbonate mineral.Based on the fine data on the structure of the mineral,the factor group and normal coordinate analyses for its infrared spectrum have been carried out.The factor group analyses indicate that the site group and factor group splittings of the internal vibration bands of CO3^2- ions do not occur and that the double bands of normal modes result from two non-equal sets of CO3^2- ions in the crystal structure,The normal coordinate analyses give the stretching force constants.bend force constants and calculated frequencies of CO3^2- ions.The calculations of potential energy distribution allow us to assign v3 and v4 to the stretching vibration and the bend vibration of CO3^2- ions.respectively. 相似文献
17.
Mihoko Hoshino Mitsuyoshi Kimata Norimasa Nishida Masahiro Shimizu 《Physics and Chemistry of Minerals》2010,37(5):255-263
Euhedral dissakisites from Trimouns dolomite mine, France, is compositionally zoned. Back-scattered electron (BSE) images
reveal that each of the described dissakisite crystals has three distinct compositional zones: normal zoned core (Mg-rich),
oscillatory zoned middle (Ca–Al-rich) and homogeneous rim (Fe–ΣREE-rich). The latter zone with Fe2+ > Mg corresponds to allanite-(Ce). Dissakisite-(Ce) also displays pronounced zoning in Fe/Mg which may suggest that the temperature
of crystallization continuously decreased from core to rim. Despite a systematic increase in Fe/Mg of the dissakisite with
an allanite rim, there is no monotonic decrease in the REE zoning: the normal zoned core and homogeneous rim are rich in La,
Ce and Pr, but the relatively REE-poor oscillatory zoned middle is relatively abundant in Y, Sm and Gd. Discontinuous variation
in REE content of the dissakisite, with the allanite rim may indicate a localized change in either the relative concentration
of various ligands or pH of the crystallizing fluid. Observations under the polarizing microscope confirm that the different
zones have simultaneous extinction. These chemical and optical observations suggest that epitaxial crystallization of dissakisite,
from Trimouns, passes through three formation stages. The ternary Fe2+–Mg2+–(Al + Fe)3+ diagram illustrates that in general dissakisite can be classified into two groups, (Al + Fe)3+-rich and an Mg-rich; dissakisite from Trimouns belongs to the former group. Chondrite-normalized REE patterns of dissakisites
from Trimouns are similar to those of allanites formed by hydrothermal fluids. In conclusion, it is clear from the above two
geochemical characteristics that dissakisites from Trimouns are of (Al + Fe)3+-type, and were derived from hydrothermal fluids. 相似文献
18.
本文用转靶四圆单晶衍射仪首次发现黄河矿(BaCe(CO_3)_2F,R3m)的一种特殊类型的双晶,其双晶轴平行c轴,双晶面∥(0001)。发现在晶体中存在着的所有衍射点均符合-h+k+l=3n或h-k+l=3n的衍射条件。这种特殊类型的双晶因其光率体对称轴完全重合,无法凭借光学手段发现。 相似文献
19.
Erokhin Yu. V. Koroteev V. A. Ivanov K. S. Khiller V. V. Farrakhova N. N. 《Doklady Earth Sciences》2020,491(1):142-145
Doklady Earth Sciences - Fluorcalciobritholite and fluorbritholite-(Ce)—rare-earth minerals from the apatite supergroup—have been found in the course of the study in monzogabbro from... 相似文献
20.
Relative oxidation states of magmas inferred from Ce(IV)/Ce(III) in zircon: application to porphyry copper deposits of northern Chile 总被引：15，自引：2，他引：15
Julian R. Ballard Michael J. Palin Ian H. Campbell 《Contributions to Mineralogy and Petrology》2002,144(3):347-364
Major- and trace-element compositions of zircons and whole rocks from 14 barren and seven ore-bearing calc-alkaline intrusions from the Chuquicamata-El Abra porphyry copper belt of northern Chile have been measured in situ by excimer laser ablation (ELA) ICP-MS. These data permit the Ce(IV)/Ce(III) ratio within zircon to be calculated using a lattice-strain model for mineral-melt partitioning of Ce(IV) and Ce(III). Zircon Ce(IV)/Ce(III) and EuN/EuN* ratios, and by inference magmatic oxidation states, generally increase from older, mafic to younger, felsic units. Within this sequence, porphyry copper mineralization is directly associated only with intrusions with zircon Ce(IV)/Ce(III)>300 and EuN/EuN*>0.4. Such trends can be understood in terms of interdependent relations between oxygen fugacity, sulfur speciation and solubility, and chalcophile element partitioning in silicate magmas. Because zircon occurs in most calc-alkaline intrusions and is resistant to subsolidus alteration, zircon Ce(IV)/Ce(III) ratios provide a useful tool for evaluating the economic potential of such rocks for magmatic-hydrothermal Cu-Au mineralization. The approach is general and may provide a means to infer relative oxidation state in a wide range of intermediate to felsic igneous rocks. 相似文献