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1.
Th-U-Pb系统数据不协调是独居石电子探针化学定年(EPMA CHIME Dating)中一种很常见的问题。独居石矿物产生数据不协调的主要原因包括:1)蚀变或重结晶造成的铅丢失;2)不同年龄域在空间上的重叠或者存在于很小颗粒上的小年龄域。独居石EPMA年龄必大于U等于0时的极端情况给出的值,即当U为0时,EPMA CHIME年龄给出的是~(208)Pb/~(232)Th年龄,这是测量区域内最老年龄的下限。当Th为0时,EPMA CHIME年龄值介于~(206)Pb/~(238)U和~(207)Pb/~(235)U年龄值之间,这是EPMA法所能得到的最老年龄的上限。分析表明,当独居石EPMA数据出现不协调时,传统等时线方法计算的年龄值误差较大。本文提出了一种处理数据不协调情况下的优化算法。该算法考虑了测量误差,并根据剩余铀的总量剔出大的离散数据。利用已公开的数据进行算法对比的结果表明,本文提出的优化算法计算结果可靠。  相似文献   

2.
Proton microprobe for chemical dating of monazite   总被引：1，自引：1，他引：0  
Although quantitative chemical analysis by proton microprobe has become an established technique, it has been rarely applied to problems in the earth sciences. The method, having lower detection limit (better than 10 ppm for U, Th and Pb) and higher spatial resolution than electron microprobe (typically 1 μm vs 3 μm), can be successfully used in geology. Here, we present a procedure for the chemical dating of monazite, (REE)PO4, by proton microprobe. The procedure is compared with electron probe microanalysis technique (EPMA).  相似文献   

3.
Chemical Th–U–total Pb (CHIME) dating of monazite by electron probe microanalyzer (EPMA) and proton microprobe (PIXE) was carried out on felsic granulites from Stary Gierałtów, Poland, which represent part of the Orlica-Śnieżnik Dome in the NE Bohemian Massif. Analyzed monazite is characterized by mosaic zoning rather than simple core-to-rim growth, and strontium contents of up to 750ppm. An isochron age of 347 ± 13Ma represents timing of amphibolite-facies metamorphism, in agreement with previously published estimates.  相似文献   

4.
U–Th–Pb dating of monazite with the electron probe microanalyser (EPMA) is increasingly documented as a reliable geochronological method offering high spatial resolution. This method has been applied on monazite from the Cévennes migmatites and granitoids from the southeast of the French Massif Central. Measurements were performed on separated grains after systematic back-scattered electron (BSE) imaging. Monazites from migmatites record two main ages: (i) a protolith age of about 550–543 Ma obtained on inherited cores, and (ii) a migmatization event between 329 ± 5 and 323 ± 3 Ma recorded by monazite rims and all other monogenetic grains. Monazite from the peraluminous Rocles pluton yields a 318 ± 3 Ma age. Finally, three granite dykes are dated at 333 ± 6, 318 ± 5 and 311 ± 5 Ma; the older dyke is the most deformed of them and is interpreted as linked to the migmatization event; the two other dykes are geochronologically, petrologically and structurally coeval with the Rocles pluton. The data constrain the timing of crustal melting following Variscan thickening in the northern Cévennes area. Migmatization of Ordovician protoliths took place at 329–323 Ma and was shortly followed by intrusion of leucogranite at 318–311 Ma. The study shows that EPMA dating of monazite can be successfully used to resolve a close succession of regional melting events.  相似文献   

5.
《Gondwana Research》2009,15(4):675-685
Chemical Th–U–total Pb (CHIME) dating of monazite by electron probe microanalyzer (EPMA) and proton microprobe (PIXE) was carried out on felsic granulites from Stary Gierałtów, Poland, which represent part of the Orlica-Śnieżnik Dome in the NE Bohemian Massif. Analyzed monazite is characterized by mosaic zoning rather than simple core-to-rim growth, and strontium contents of up to 750ppm. An isochron age of 347 ± 13Ma represents timing of amphibolite-facies metamorphism, in agreement with previously published estimates.  相似文献   

6.
独居石是华南产铀花岗岩中常见的含铀副矿物.龙华山岩体是粤北诸广山复式岩体中一个重要的产铀花岗岩,该岩体的独居石具有蚀变晕圈现象.但是,该岩体中独居石蚀变晕圈的结构和成分特征以及对铀成矿的指示意义尚未开展研究.本文利用电子探针(EPMA)对龙华山岩体的独居石蚀变晕圈开展结构和成分研究.测试结果表明:独居石蚀变晕圈是从内到...  相似文献   

7.
After a decade of studies and development, it is now accepted that reliable U–Th–total Pb isochron ages can be calculated for monazite using an electron microprobe at μm scale, either directly on thin sections or on separated grains mounted in polished section. The potential for determining U–Th–Pb chemical ages from other U- and Th-enriched phases has been investigated compared to chemical monazite-dating results for which individual spot-age precisions of 20 to 100 Ma can be achieved from individual spot analyses. Using isochron plots for monazite, the age homogeneity of a given population of data can be assessed and, depending upon the number of analyses (n  50), a precision of 5 to 10 Ma can be obtained. The U content in xenotime widely varies from less than 0.1 wt.% up to 3 wt.%, but Th rarely exceeds 1 wt.%. As a consequence, the amount of radiogenic Pb produced during a given period remains significantly lower for xenotime than for monazite, leading to a lower precision (± 20 Ma) on the mean ages. Xenotime, however, appears to remain as a closed system, but common Pb must be carefully checked. Furthermore, the electron-microprobe technique (EPMA) allows controlling any age discrepancy on xenotime grains as small as 10–20 μm that cannot be dated by other isotopic methods. Such xenotime ages can be useful when studying the monazite–xenotime equilibrium. The electron microprobe is not the most reliable method for dating zircon since U and Th concentrations are generally low and common Pb is not negligible. Nevertheless, the spatial resolution of EPMA coupled with isotope methods allows conclusive in situ studies about radiogenic Pb mobility and metamictization. Thorite does not seem suitable for dating with either isotope methods or EPMA because of continuous radiogenic Pb loss. Conversely, the oxide phases, thorianite and baddeleyite are robust minerals with closed systems. They are rather rare and seem to incorporate negligible common Pb, making EPMA a method of choice for dating them. For thorianite, the precision on the mean age can be similar as that obtained for monazite, or even better, while the precision for baddeleyite cannot be significantly better than 20 to 50 Ma due to the limited amount of U ( 0.1%) and the lack of Th.  相似文献   

8.
The effect of carbon or graphite coating on the adsorption of gold cyanide on pyrite was investigated with pure pyrite and a pyrite concentrate. In the carbon or graphite contaminated pyrite systems carbon and graphite not only acted as gold sorbents, but also enhanced gold adsorption on pyrite. The carbon coating enhanced gold adsorption on pyrite to a larger extent, in comparison with the graphite coating. The carbon or graphite coating on pyrite reduced the negativity of the pyrite surfaces, and hence improved the physical adsorption of gold cyanide on pyrite. In addition, the highly conductive coating of carbon or graphite on pyrite could enhance electron transfer in the electrochemical reactions occurring in the chemical adsorption of gold and gold reduction on pyrite. The preg-robbing by pyrite or the graphite-coated pyrite was reduced and further eliminated at higher cyanide concentrations. However, gold adsorption on the carbon-coated pyrite could not be prevented even at higher cyanide concentrations due to gold adsorption on the carbon coating. In comparison with pure pyrite, the pyrite concentrate had a higher capacity adsorbing gold, due to the presence of carbonaceous matter in the pyrite concentrate. Fine grinding intensified the smearing of carbon or graphite on the mineral particles, resulting in a larger extent of enhancement in the preg-robbing of the concentrate by the carbon or graphite coating.A diagnostic elution of the preg-robbing pyrite samples indicated that the reduction of gold at the pyrite surfaces was the dominant mechanism for gold adsorption on pyrite, followed by physical and chemical adsorption. Surface topological studies by SEM/EDX showed that gold adsorbed at defect sites on pyrite surfaces. For the pyrite with a 5% carbon coating, gold was observed to adsorb not only at the defect sites, but also at the smooth surfaces with carbon present. For the pyrite with a 5% graphite coating, carbon was also found at the pyrite surfaces, but gold was only detected at the defect sites. XPS studies revealed that part of the gold physically and chemically adsorbed on pyrite or pyrite coated with carbon or graphite. Some gold cyanide was reduced at the pyrite surfaces, with the sulphide ions of pyrite being oxidised to elemental sulphur.  相似文献   

9.
The effect of carbon or graphite coating on the adsorption of gold cyanide on pyrite was investigated with pure pyrite and a pyrite concentrate. In the carbon or graphite-contaminated pyrite systems carbon and graphite not only acted as gold sorbents, but also enhanced gold adsorption on pyrite. The carbon coating enhanced gold adsorption on pyrite to a larger extent, in comparison with the graphite coating. The carbon or graphite coating on pyrite reduced the negativity of the pyrite surfaces, and hence improved the physical adsorption of gold cyanide on pyrite. In addition, the highly conductive coating of carbon or graphite on pyrite could enhance electron transfer in the electrochemical reactions occurring in the chemical adsorption of gold and gold reduction on pyrite. The preg-robbing by pyrite or the graphite-coated pyrite was reduced and further eliminated at higher cyanide concentrations. However, gold adsorption on the carbon-coated pyrite could not be prevented even at higher cyanide concentrations due to gold adsorption on the carbon coating. In comparison with pure pyrite, the pyrite concentrate had a higher capacity adsorbing gold, due to the presence of carbonaceous matter in the pyrite concentrate. Fine grinding intensified the smearing of carbon or graphite on the mineral particles, resulting in a larger extent of enhancement in the preg-robbing of the concentrate by the carbon or graphite coating.A diagnostic elution of the preg-robbing pyrite samples indicated that the reduction of gold at the pyrite surfaces was the dominant mechanism for gold adsorption on pyrite, followed by physical and chemical adsorption. Surface topological studies by SEM/EDX showed that gold adsorbed at defect sites on pyrite surfaces. For the pyrite with a 5% carbon coating, gold was observed to adsorb not only at the defect sites, but also at the smooth surfaces with carbon present. For the pyrite with a 5% graphite coating, carbon was also found at the pyrite surfaces, but gold was only detected at the defect sites. XPS studies revealed that part of the gold physically and chemically adsorbed on pyrite or pyrite coated with carbon or graphite. Some gold cyanide was reduced at the pyrite surfaces, with the sulphide ions of pyrite being oxidised to elemental sulphur.  相似文献   

10.
Monazite in granulite facies metatexite migmatites (Christie Gneiss) hosting the Challenger Au deposit, South Australia, records a series of growth and resorption stages over a c. 60 Myr period between 2470 and 2410 Ma. A combination of electron microprobe X‐ray mapping and in situ ion‐microprobe dating was used to delineate and date five compositional domains. The oldest prograde metamorphic components are preserved in granoblastic gneisses surrounding the deposit, and as small high‐Y cores in large monazite grains in Au‐bearing migmatites. In metatexite leucosomes, these cores were partially resorbed prior to the growth of large high‐Th monazite domains that crystallized during partial melting and stromatic migmatite development at c. 2443 Ma. Subsequent heating to biotite dehydration conditions (c. 850 °C at 7 kbar) caused further partial melting roughly 10–15 Myr later, giving rise to c. 2428 Ma domains surrounding partly resorbed 2443 Ma grains that were entrained in the higher‐temperature melts. This period of partial melting coincided with isoclinal folding culminating in dextral transpression and represents the most likely window for remobilization of Au‐bearing polymetallic sulphide melts into low‐strain domains. Localized reaction of residual melt with the granulite facies assemblage during cooling gave rise to narrow high‐Y rims dated at 2414 ± 7 Ma. Although monazite from unmineralized granoblastic gneisses and migmatitic ore zones display the same range of U‐Pb dates, monazite in migmatites displays a higher overall Ca + Th + U content, indicating that compositional heterogeneities between ore zones and host rocks developed prior to 2470 Ma, perhaps a consequence of the hydrothermal alteration inferred to have accompanied gold mineralization.  相似文献   

11.
EPMA U-Th-Pbtotal dating in U- and Th bearing minerals (e.g., monazite, zircon, and xenotime) is a low-cost and reliable technique used for retrieving age information from detrital, diagenetic and low to high-T metamorphic, as well as magmatic rocks. Although, the accuracy on measured ages obtained using EPMA is considered to be poor compared to isotopic ages, the superior spatial resolution, ability to integrate textural and age information by in-situ measurement, lack of sample damage and easier and cheaper data generation in EPMA make chemical dating a very valuable tool to decipher diverse petrological processes.This contribution presents an improved analytical protocol to obtain precise estimates of U, Th and Pb concentrations in xenotime. Results were tested on monazite standard (Moacyr pegmatite, Brazil; TIMS age: 487 ± 1 Ma) as the reference material. The proposed analytical protocol has been successfully applied to achieve an analytical uncertainty of less than 10% in U, Th and Pb measurements in xenotime. The protocol was further used to resolve polygenetic xenotime ages (ca. 1.82, 1.28 and 0.93 Ga) in metapelite samples from the Mangalwar Complex, Northwestern India. Monazites in the same samples were also analyzed and found to preserve the two younger ages (i.e., ca. 1.28 and 1.0 Ga). The obtained ages from the xenotime and monazite very well corroborate with the earlier published ages from the area validating the proposed analytical protocol.  相似文献   

12.
邹家山铀矿床伴生重稀土元素的赋存特征   总被引：1，自引：0，他引：1  
初步研究发现,相山矿田邹家山矿床中伴生有较高的重稀土元素,回收这些珍稀的资源和探索其成因具有重要的意义,而查明这些伴生稀土在铀矿床中的赋存特征是前期基础性工作。为此本文采用电子探针和激光剥蚀电感耦合等离子体质谱分析了邹家山铀矿床中稀土元素的赋存状态。结果显示：该矿床稀土矿物主要为独居石、氟碳钙铈矿和磷钇矿;独居石、氟碳钙铈矿的LREE/HREE>1,为轻稀土富集型;而磷钇矿的LREE/HREE<1,为重稀土富集型。沥青铀矿、钛铀矿、铀钍石、铀石、钍石、锆石等铀钍矿物的稀土特征为重稀土富集型;铀钍矿物稀土总量（∑REE+Y）较高,为（3 805.78~65 307.00）×10-6,LREE/HREE<1,为0.01~0.80,平均为0.29。其他伴生矿物磷灰石、钾长石为轻稀土富集型,萤石为轻、重稀土富集型两类都有,而伊利石、黄铁矿的轻重稀土无明显相对富集。重稀土在磷钇矿和铀钍矿物中以类质同象形式存在,少量赋存于伴生矿物。  相似文献   

13.
胶东乳山英格庄金矿碲化物的发现及其意义   总被引：8，自引：2，他引：6  
本文通过电子探针微束分析,在胶东牟平-乳山成矿带内的英格庄金矿发现碲银矿、辉碲铋矿,并在胶东地区首次发现楚碲铋矿,该矿物系列以复杂的连生关系呈细小片状产出于白云石及石英矿物颗粒间。碲化物电子探针化学成分结果显示本区碲化物普遍贫碲。依据碲化物及其共生矿物的产出关系和矿物化学成分,推测其形成顺序为黄铁矿→镍黄铁矿→辉碲铋矿→楚碲铋矿→碲银矿。依据碲化物矿物共生组合对体系中碲化物形成时的fTe2和fS2进行了限定,log fTe2范围为-19.5~-11.2,log fS2上限为-16.8;并试图对碲的来源及其地质意义进行探讨,认为英格庄金矿中碲化物的发现揭示了深成幔源的信息,鉴于碲与金相近的地球化学特征和密切关系,认为金矿赋矿围岩荆山群和昆嵛山杂岩体提供成矿物质来源的可能性不大,而早白垩世的构造-岩浆活动特别是壳幔物质的交换过程与金成矿关系更为密切。  相似文献   

14.
In this study,an electron microprobe analyzer(EMPA) was used to map the spatial distribution and the occurrence of invisible gold in pyrite from the Liulincha gold ore belt.EPMA data show that gold mainly occurs as submicroscopic-microscopic inclusions.From the contrast of the major guide elements of pyrite from the Liulincha gold ore belt and those from four hydrothermal-type gold deposits in the Jiaodong region,we can see the pyrites were formed in two stages:the pyrite from wall rock is mainly sedimentogenic,with simple structure;and the pyrite from ore body experienced early sedimentary process to late hydrothermal activity,the pyrite is regular in crystal form and exhibits fractured structure.  相似文献   

15.
New glass reference materials GSA-1G, GSC-1G, GSD-1G and GSE-1G have been characterised using a prototype solid state laser ablation system capable of producing wavelengths of 193 nm, 213 nm and 266 nm. This system allowed comparison of the effects of different laser wavelengths under nearly identical ablation and ICP operating conditions. The wavelengths 213 nm and 266 nm were also used at higher energy densities to evaluate the influence of energy density on quantitative analysis. In addition, the glass reference materials were analysed using commercially available 266 nm Nd:YAG and 193 nm ArF excimer lasers. Laser ablation analysis was carried out using both single spot and scanning mode ablation. Using laser ablation ICP-MS, concentrations of fifty-eight elements were determined with external calibration to the NIST SRM 610 glass reference material. Instead of applying the more common internal standardisation procedure, the total concentration of all element oxide concentrations was normalised to 100%. Major element concentrations were compared with those determined by electron microprobe. In addition to NIST SRM 610 for external calibration, USGS BCR-2G was used as a more closely matrix-matched reference material in order to compare the effect of matrix-matched and non matrix-matched calibration on quantitative analysis. The results show that the various laser wavelengths and energy densities applied produced similar results, with the exception of scanning mode ablation at 266 nm without matrix-matched calibration where deviations up to 60% from the average were found. However, results acquired using a scanning mode with a matrix-matched calibration agreed with results obtained by spot analysis. The increased abundance of large particles produced when using a scanning ablation mode with NIST SRM 610, is responsible for elemental fractionation effects caused by incomplete vaporisation of large particles in the ICP.  相似文献   

16.
Understanding the mechanisms of parent-daughter isotopic mobility at the nanoscale is key to rigorous interpretation of Ue The Pb data and associated dating. Until now, all nanoscale geochronological studies on geological samples have relied on either Transmission Electron Microscope(TEM) or Atom Probe Microscopy(APM) characterizations alone, thus suffering from the respective weaknesses of each technique. Here we focus on monazite crystals from a ~1 Ga, ultrahigh temperature granulite from Rogaland(Norway). This sample has recorded concordant UeP b dates(measured by LA-ICP-MS) that range over 100 My, with the three domains yielding distinct isotopic Ue Pb ages of 1034 ± 6 Ma(D1; Srich core), 1005 ± 7 Ma(D2), and 935 ± 7 Ma(D3), respectively. Combined APM and TEM characterization of these monazite crystals reveal phase separation that led to the isolation of two different radiogenic Pb(Pb*) reservoirs at the nanoscale. The S-rich core of these monazite crystals contains Cae Srich clusters, 5 -10 nm in size, homogenously distributed within the monazite matrix with a mean interparticle distance of 40 -60 nm. The clusters acted as a sink for radiogenic Pb(Pb*) produced in the monazite matrix, which was reset at the nanoscale via Pb diffusion while the grain remained closed at the micro-scale. Compared to the concordant ages given by conventional micro-scale dating of the grain,the apparent nano-scale age of the monazite matrix in between clusters is about 100 Myr younger, which compares remarkably well to the duration of the metamorphic event. This study highlights the capabilities of combined APM-TEM nano-structural and nano-isotopic characterizations in dating and timing of geological events, allowing the detection of processes untraceable with conventional dating methods.  相似文献   

17.
TWO EPISODES OF MONAZITE CRYSTALLIZATION DURING METAMORPHISM AND CRUSTAL MELTING IN THE EVEREST REGION OF THE NEPALESE HIMALAYA  相似文献   

18.
Trace element concentrations in gold grains from various geological units in South Africa were measured in situ by field emission‐electron probe microanalysis (FE‐EPMA), laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and synchrotron micro X‐ray fluorescence spectroscopy (SR‐μ‐XRF). This study assesses the accuracy, precision and detection limits of these mostly non‐destructive analytical methods using certified reference materials and discusses their application in natural sample measurement. FE‐EPMA point analyses yielded reproducible and discernible concentrations for Au and trace concentrations of S, Cu, Ti, Hg, Fe and Ni, with detection limits well below the actual concentrations in the gold. LA‐ICP‐MS analyses required larger gold particles (> 60 μm) to avoid contamination during measurement. Elements that measured above detection limits included Ag, Cu, Ti, Fe, Pt, Pd, Mn, Cr, Ni, Sn, Hg, Pb, As and Te, which can be used for geochemical characterisation and gold fingerprinting. Although LA‐ICP‐MS measurements had lower detection limits, precision was lower than FE‐EPMA and SR‐μ‐XRF. The higher variability in absolute values measured by LA‐ICP‐MS, possibly due to micro‐inclusions, had to be critically assessed. Non‐destructive point analyses of gold alloys by SR‐μ‐XRF revealed Ag, Fe, Cu, Ni, Pb, Ti, Sb, U, Cr, Co, As, Y and Zr in the various gold samples. Detection limits were mostly lower than those for elements measured by FE‐EPMA, but higher than those for elements measured by LA‐ICP‐MS.  相似文献   

19.
海南石碌铁矿独居石的成因类型、化学定年及地质意义   总被引：1，自引：0，他引：1  
海南石碌铁矿是我国最大的富赤铁矿矿床,同时伴生有钴、铜等多金属矿产。轴向北西-南东向的复式向斜是石碌铁、钴铜矿体的主要控矿构造,富铁矿和钴铜矿的形成与该褶皱变形及伴随的韧性剪切和高温塑性流动有着密切的关系。为获得该构造变形的年代学信息和证实构造变形对成矿物质的富集影响,本文开展了石碌铁矿近矿围岩—石碌群第六层透辉石透闪石岩中独居石的显微结构观察和电子探针化学Th-U-Pb定年(CHIME法)。显微结构观察发现独居石往往沿岩石面理定向分布,且具典型的球冠结构,表现为围绕独居石核部向外依次出现磷灰石、褐帘石、绿帘石同心环。电子探针分析结果表明这些独居石为Ce-La-Nd磷酸盐[(Ce,La,Nd,Th)PO4],具富钍独居石端元组分。ThO 2含量范围(0.78%~4.61%)、稀土特征以及独居石的产出特征均暗示了其为同构造变质成因。电子探针CHIME化学定年结果表明独居石的年龄变化范围为614~397Ma,并具有两个峰值年龄:即主峰值ca.455Ma和次峰值ca.564Ma。低的ThO 2(0.78%~1.65%),PbO(0.02%~0.04%)和CaO(0.50%~0.97%)含量,以及高的Th/U比值(23.06~53.11)暗示了构成ca.564Ma的独居石是早期剪切变形事件的产物。而在随后剪切变形过程中独居石在低角闪岩相变质条件下以及碱性变质流体诱导下发生了溶解-再沉淀,形成了具ca.455Ma年龄的补丁状成分区。该过程引起了U-Pb体系的局部重置,形成的独居石具有变化较大的ThO 2(0.92%~4.61%)、PbO(0.01%~0.08%)和CaO(0.28%~1.58%)含量范围以及Th/U值(24.83~52.86)。在剪切变形之后,早期变质成因的独居石在绿片岩相退变质作用过程中及富Ca、Fe、Si、Al流体参与的条件下,经不平衡反应形成了磷灰石-褐帘石-绿帘石球冠物,反应机制以独居石和球冠矿物间的元素扩散动力学为主。该反应暗示了REE、Y、Th等元素发生了迁移,并可能引起边部独居石的部分Pb丢失。结合华南的构造演化,年龄谱主峰值455Ma代表了与华南加里东造山运动有关的区域变质和动力变质作用事件年龄,是加里东运动在海南岛的响应;次峰值年龄564Ma对应着冈瓦纳泛非事件,暗示了华南在晚新元古代-早古生代与冈瓦纳大陆具有亲缘性,华南加里东运动引起陆内造山过程可能与冈瓦纳大陆的聚合碰撞事件有关。因此,晚新元古代-早古生代造山事件对海南岛构造演化历史具重要影响。此外,该构造运动使石碌群发生褶皱变形,伴随产生的变质流体使铁、钴铜成矿元素进一步活化和富集,对石碌铁、钴铜矿的富集有着重要影响。  相似文献   

20.
邛莫金矿床中的硒辉锑矿   总被引：6，自引：0，他引：6  
刘家军  刘建明 《矿物学报》1998,18(4):445-451
硒辉锑矿产于西秦岭邛莫金矿床中。与其共生的矿物有灰硒汞矿、灰硒铝矿、硒锑矿、硒块硫锑铜矿、硒镍矿、自然金以及石英、重晶石等。该矿物显微硬度VHN50＝68．25～128．0kg／mm2,平均101．26kg／mm2,相当于摩氏硬度3．15、30个测点的电子探针分析结果（％）：Sb57．75～66．79（平均63．25）,S11．86～21．62（平均17．30）,Se12．82～29．12（平均19．27）,据其平均值计算的化学分子式为：Sb1．99（S2．07,Se0．93）3．00,简写式为Sb2（S,Se）3。代表性的反射率（％）：（470nm）Rα’＝45．33,Rγ’＝31．03;（550nm）Rα’＝46．75,Rγ’＝33．63;（590nm）Rα’＝46．06,Rγ’＝：33．50;（650nm）Rα’＝45．18,Rγ’＝31．49。对两个Se含量仅达3％～5％的辉锑矿粉晶分析所得晶胞参数值为：a＝1．1209～1,1212nm,b=1．1299～1,1303nm,c＝0．3847～0,3849nm。与辉锑矿相比十分相似。  相似文献   

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