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1.
熊小林  朱金初 《矿物学报》1995,15(4):451-456
本文根据前人关于云母和黄玉的F-OH交换实验成果,分别建立了云母和黄玉的F-OH交换平衡常数方程,并系统阐述了推导这些方程的热力学原理以利用它们来估算云母+黄玉平衡组合形成温度和共存流体组成的方法,最后讨论了这一方法的适用条件和存在问题。  相似文献   

2.
利用中子辐照改色法把天然无色黄玉改成蓝色黄玉,对天然黄玉和改色后的蓝黄玉分别进行了常规检测、X-荧光测试、紫外-可见光谱测试及红外光谱测试研究。结果表明:改色前后黄玉的比重、折射率、成分都没有明显的变化;其紫外-可见光光谱、红外光谱存在一定的差异。这些差异为鉴别天然黄玉与辐照改色黄玉提供了依据。  相似文献   

3.
晚期富挥发分的黄玉花岗岩广泛而零星地产于英格兰西南部含Sn-Cu多金属矿化的S型黑云母花岗岩岩基中。St.Austell地区的最新观察资料查明了其野外关系,并论证了影响花岗质容矿主岩和沉积岩容矿主岩的电气石化晕的意义。黄玉花岗岩接触带通常以显示出无定向固结结构、具有石英-电气石晶洞的伟晶岩带为标志,较小的侵入黄玉花岗岩岩席在其围岩中具有对称状电气石化晕。黄玉花岗岩矿物组成复杂,除钠长石、正长石和石英外,还含原生黄玉、铁锂云母或锂云母、磷铝锂石以及各种富Nb-Ta的副矿物。在化学成分上,它们与黑云母花岗岩截然不同,特别富Li、F、P、Nb、Ta、Ga、Rb。黑云母花岗岩的晚期分异产物包括电气石花岗岩,但这部分异趋势主要涉及到B的增高,Li、F或P的变化较小我们认为,黄玉花岗岩可能不是由英格兰西南部的黑云母花岗岩浆(被属于黑云母花岗岩岩套的流纹斑岩岩脉所侵入)经结晶分异所派生,而是在钾质基性岩浆作用期间由岩基之下的熔融残留物经有限部分熔融而形成。与其它富挥发分的花岗质岩石的对比表明,英格兰西南部的黄玉花岗岩与锂伟晶岩(如Tanco)、火山玻璃(如Macusani)和其它的黄玉花岗岩(如Seward半岛)具有一些共同的重要特征。这些岩石可能代表一类基本相似的富挥发分花岗岩浆。我们认为它们的形成可能受以前曾产生过更为“正常”花岗岩浆的下地壳熔融残留物的有限部分熔融所控制,尽管目前仍有争议。  相似文献   

4.
白云鄂博矿床氟金云母的矿物学研究   总被引:3,自引:1,他引:2  
徐金沙  沈敢富 《矿物学报》2005,25(3):213-216
内蒙白云鄂博REE-Nb-Fe矿床广泛分布的“金云母”,以F含量〉〉H2O^+含量为其鲜明特色。按∑(O+F)=12计算的金云母化学式表明,其附加阴离子中,绝大多数F〉OH。根据国际矿物协会(IMA)新矿物及矿物命名委员会(CNMMN)的规定,F〉OH(离子摩尔数)的金云母,应称氟金云母,属云母族的独立矿物种。检索IMA CNMMN公布的已知矿物种名录,均无氟金云母条目。为此,按新矿物要求,对该矿物作了详尽而系统的矿物学研究;同时还对金云母组的矿物作了分类。  相似文献   

5.
新矿物栾锂云母[KLiAl1.5□0.5(Si3.5Al0.5)O10(OH,F)2]发现于豫西卢氏县官坡镇稀有金属花岗伟晶岩密集区309号脉。其主要共/伴生矿物有石英、"栾锂云母的富氟类似物"、羟磷锂铝石、铯沸石、钽铋矿及贫Na、Ca但富Li、OH或F电气石等。其次有钽铁矿、钽锰矿、三锂云母、多硅锂云母(?)、细晶石族矿物、钠长石(An≤4)和锂辉石、氧钠细晶石及氟钙细晶石等细晶石族矿物;偶尔与白云母等共生。根据产出特征,借鉴相关成岩-成矿实验和流体包裹体研究成果,推测栾锂云母主要从一类低熔的富挥发份和活性组份,以及富亲石性成矿元素的岩浆-热液过渡流体中直接结晶所成。栾锂云母多呈鳞片状集合体产于309伟晶岩脉边缘带或/和其内的单矿物细脉中。其单个片径大都小于1 mm。矿物具玻璃光泽,解理面显珍珠光泽;沿(001)面的解理极完全;显微硬度平均为102 kg/mm2,约相当于摩氏硬度3;实测密度为2.851 g/cm3,计算密度值2.868 g/cm3。正延性,二轴晶,负光性,2V=36°40°;折光率:Np=1.5474,Nm=1.5700,Ng=1.5729。光性定位:Np=X=c,Nm=Y=b,Ng=Z=a。矿物大都发育波状消光。化学成分(wB/%)SiO251.65,TiO20.01,Al2O323.50,FeO 0.72,CaO 0.02,MnO 0.22,MgO 0.04,Na2O 0.15,K2O 11.62,Li2O 3.80,Rb2O0.78,Cs2O 0.53,F 3.85,H2O+2.82,F≡O-1.62,合计98.09.%。根据O+OH+F=12 apfu,计算的经验化学式为(K1.01Rb0.03Cs0.02Na0.02)Σ1.08(Li1.04Al1.39Fe0.04Mn0.01)Σ2.48(Si3.51Al0.49)Σ4.00(O9.89OH0.11)Σ10.00(OH1.17F0.83)Σ2.00。简化式:KLiAl1..5□0.5(Si3.5Al0.5)O10(OH,F)2,理想化学式为KLiAl1.5□0.5(Si3.5Al0.5)O10(OH)2。与沃洛欣云母RbLiAl1.5□0.5(Si3.5Al0.5)4O10F2比较,新成员是沃洛欣云母间阳离子的钾类似物,以及附加阴离子的羟占优的类似物。栾锂云母晶体结构的精测显示,矿物属单斜晶系,空间群C2/c。晶胞参数:a=0.51861(7)nm,b=0.89857(13)nm,c=1.9970(3)nm,V=0.9265(2)nm3;β=95.420(3)°,Z=4。栾锂云母为2M1多型。其晶体结构精测的R因子(R1=0.098)欠佳,是由于矿物生成后,受到构造干扰所致。栾锂云母(Luanshiweiite)的命名旨在纪念我国知名的伟晶岩石学家栾世伟教授(192840°;折光率:Np=1.5474,Nm=1.5700,Ng=1.5729。光性定位:Np=X=c,Nm=Y=b,Ng=Z=a。矿物大都发育波状消光。化学成分(wB/%)SiO251.65,TiO20.01,Al2O323.50,FeO 0.72,CaO 0.02,MnO 0.22,MgO 0.04,Na2O 0.15,K2O 11.62,Li2O 3.80,Rb2O0.78,Cs2O 0.53,F 3.85,H2O+2.82,F≡O-1.62,合计98.09.%。根据O+OH+F=12 apfu,计算的经验化学式为(K1.01Rb0.03Cs0.02Na0.02)Σ1.08(Li1.04Al1.39Fe0.04Mn0.01)Σ2.48(Si3.51Al0.49)Σ4.00(O9.89OH0.11)Σ10.00(OH1.17F0.83)Σ2.00。简化式:KLiAl1..5□0.5(Si3.5Al0.5)O10(OH,F)2,理想化学式为KLiAl1.5□0.5(Si3.5Al0.5)O10(OH)2。与沃洛欣云母RbLiAl1.5□0.5(Si3.5Al0.5)4O10F2比较,新成员是沃洛欣云母间阳离子的钾类似物,以及附加阴离子的羟占优的类似物。栾锂云母晶体结构的精测显示,矿物属单斜晶系,空间群C2/c。晶胞参数:a=0.51861(7)nm,b=0.89857(13)nm,c=1.9970(3)nm,V=0.9265(2)nm3;β=95.420(3)°,Z=4。栾锂云母为2M1多型。其晶体结构精测的R因子(R1=0.098)欠佳,是由于矿物生成后,受到构造干扰所致。栾锂云母(Luanshiweiite)的命名旨在纪念我国知名的伟晶岩石学家栾世伟教授(19282012)。新矿物及其命名,业已得到IMA CNMNC批准(批准文号IMA2011-102)。栾锂云母的原型标本典藏在北京中国地质博物馆内(注册号:M11797)。  相似文献   

6.
位于苏州A型花岗岩主体相晚阶段衍生物(碱长花岗岩)上部,基本上由新矿物-氟铁云母组成的单矿物岩,具有独特的产状、结构、构造、岩石化学、矿物学、地球化学和成矿作用特征。种种典型的宏观、微观地质特征和合成氟铁云母的实验资料揭示,氟铁云母岩主要是从A型花岗岩浆演化至晚阶段熔离出来的富F,Fe和亲石性矿化元素及富碱性元素(且K>>Na)而相对贫水的高温硅酸盐熔体中直接结晶固化所成。氟铁云母岩应属一种新的岩浆岩,依产地命名为姑苏岩。姑苏岩拟归入岩浆云英岩范畴为宜。提出了包括姑苏岩、含黄玉的石英-氟铁云母云英岩(苏州岩)和氟铁云母碱长花岗岩等在内的苏州A型花岗岩的成岩、成矿模式。  相似文献   

7.
新疆白石头泉高铷氟花岗岩不同相带云母成分及其演化   总被引:1,自引:1,他引:0  
白石头泉含黄玉花岗岩体在露头上显示很好的岩性分带,从下至上依次为:淡色花岗岩(a带)、含天河石花岗岩(b带)、天河石花岗岩(c带)、含黄玉天河石花岗岩(d带)和黄玉钠长花岗岩(e带).岩体组成矿物主要为石英、钾长石(部分富铷的为天河石)、钠长石、黄玉和云母,副矿物为锰铝榴石和萤石.总体说来,从a带到c带,云母的Al、Mn、F和Rb含量递增,Fe、Mg和Ti含量递减;Li含量从a带到b带和c带递增,但b带和c带之间变化不明显.从c带到e带,随着Fe、Mg和Ti的减少,总体上表现为Al、Li递增,F、Mn和Rb递减的演化方向,但Li、F、Mn和Rb在c带和d带之间变化不明显,d带和e带之间却表现出急剧的变化.e带中的次生云母与原生云母相比,前者F、Li高而Al低,从a带到e带,Na K变化不明显.云母成分的这些变化特征与岩体的演化趋势相一致.白石头泉岩体与世界上其他地方类似花岗岩相比,没有出现锂云母这种高度富锂矿物,这可能与岩体中锂含量较低有关.  相似文献   

8.
本文借助主成分分析证明了花岗岩类中黑云母的Fe~(3+)、Fe~(2+)和(OH+F)主要的数量关系不表现为氧羟铁云母置换,还讨论了水不足和水过剩对云母分子式计算结果的影响,进而提出了当处理一批未受明显脱羟基氧化的云母,尤其是当其中包括明显水过剩云母时,宜优先采用O=22计算分子式方案等建议。  相似文献   

9.
根据含黄玉岩石的矿物学、地质和地球化学以及黄玉中的流体包裹体特征研究,借鉴富F酸性岩体系的成岩成矿实验新成果,推出了新的黄玉成岩-成矿模式,力证黄玉是以富氟低熔岩浆结晶为主的多成因产物,不否定黄玉的交代蚀变和变质成因,认为盲目滥用和过分夸大变质(含交代)作用及其成岩、成矿的极端重要性和普适性不可取。  相似文献   

10.
江西雅山黄玉锂云母花岗岩中铯矿物的电子探针研究   总被引:3,自引:2,他引:3  
江西宜春雅山花岗岩是典型的高度分异型稀有金属花岗岩。通过对其最晚期花岗岩———黄玉锂云母花岗岩的钻孔样品和近地表样品的研究,发现岩体中主要有两种铯矿物:铯沸石和富铯锂云母。铯沸石是第一次在花岗岩中发现,其产状主要有两类:一类包裹于石英中,颗粒小,只有2~10μm,单个颗粒成分均匀,Si/Al比值和Poll值(%)犤=100×Cs/(Na+K+Rb+Cs)犦分别为2.13~2.65和57~89;另一类赋存于钠长石晶隙间,颗粒大,多为几百μm,单个颗粒成分不均匀,Si/Al比值和Poll值分别为2.20~2.45和75.6~88.2。富铯的云母类矿物分布较普遍,主要呈四种产状,分别为钾长石雪球中的带状富铯锂云母、云母边部的环边富铯云母、叶脉纹理状富铯云母和主矿物中的富铯云母包裹体,并根据成分中Si/Al比值和Cs的摩尔分数(%)犤=100×Cs/(Cs+K)犦,将富铯的云母类矿物分为含铯锂云母、富铯锂云母和铯锂云母三类,其中Cs替代K,Cs完全替代K形成的铯锂云母可能是锂云母系列中的铯端员新矿物。钻孔样品中的富铯云母类矿物以带状结构和环边结构最为发育,且成分主要属于含铯锂云母和富铯锂云母这两个部分,而近地表样品中则以环边结构和叶脉纹理状结构为特征,成分多为铯锂云母。铯沸石和富铯云母的产状及地球化学特征均表明,雅山岩体原始岩浆中碱金属经  相似文献   

11.
周凤英  朱金初 《矿物学报》1995,15(3):259-264
癞子岭黄玉云英岩矿物中流体-熔融包裹体研究揭示黄玉云英岩是岩浆-热液过渡阶段的结晶产物。而黄玉云英岩中岩浆作用与交代作用特征并存现象则是低温成岩熔体在结晶过程中共存的热液对已形成的矿物产生水岩反应的结果。  相似文献   

12.
论岩浆成因的黄玉单矿物岩   总被引:2,自引:0,他引:2  
沈敢富 《地质论评》1997,43(6):607-615
业已在自然界发现中深成相,超浅成相和良好封闭相的岩浆成因黄玉单矿物岩,拥有宏观,微观岩浆成因标志,得到有关富挥发分酸性岩体成岩,成矿实验成果的有力佐证,属一类新的岩浆岩。这类岩石的分类实践表明,它们宜归入岩浆成的云英岩类范畴。有理由预见,自然界存在有黄玉单矿物岩的火山类似物,尚待发现与研究。  相似文献   

13.
秦善  曹正民 《地质论评》1995,41(4):378-383
晶体形态是描述矿物最直观的数据。本文对江西漂塘钨矿床中的5个黄玉晶体进行了晶体测量、投影、计算和实际晶体的立体图绘制,并对其形态特征进行了分析和总结。  相似文献   

14.
F. A. Letnikov 《Petrology》2008,16(4):319-334
The paper presents the first data obtained on topaz granites from dikes in columbite-bearing granites of the Kokchetav block, northern Kazakhstan. The columbite-bearing granites (398 ± 3 Ma, Rb-Sr method) compose large massifs and ubiquitously contain columbite as an accessory mineral in amounts from a few to a few dozen grams per ton. The topaz granites make up dikes up to 70–100 m long and 0.4–1.5 m thick, which have sharp contacts with the host granites. The composition of the topaz granites is as follows: albite ~50%, potassic feldspar ~24–26%, quartz ~20%, topaz 3–5%, biotite and muscovite ~1%. Topaz occurs in inner contact zones in the form of large (3–4 cm) crystals, which grew inward from dike contacts and is ubiquitous in the fine-grained groundmass as small (no larger than 0.05 mm) crystals. The ore minerals in the topaz granites (zircon, thorite, bastnaesite, Y-cerite, monazite, Y-fluorite, W-ixiolite, tantalite, columbite, and uraninite) developed as very small grains, which can be identified only under a microprobe and electron microscope. W-ixiolite was found only in topaz crystals. The topaz granites are rich in albite, contain Na > K and F concentrations from 0.2 to 0.97 wt %. Compared to the host columbite-bearing granites, the topaz granites are 10–15 times richer in Ta and Li, 3-8 times richer in Rb, Cs, Nb, Sn, F, and Be but 1.2–2 times poorer in U, Th, and REE. The columbite-bearing granites have Ta/Nb = 1: 20, while this ratio in the topaz granites is 1: 3, a fact highlighting the enrichment of the granites in Ta and their geochemical autonomy with respect to columbite-bearing granites.  相似文献   

15.
Phase relations of F-rich Kymi equigranular topaz granite have been investigated experimentally at 100–500 MPa as a function of water activity and F content. Fluorite and topaz can crystallize as liquidus phases in F-rich peraluminous systems, but the F content of the melt should exceed 2.5–3.0 wt% for the crystallization of topaz. In peraluminous F-bearing melts containing more than 1 wt% F, topaz and muscovite are expected to be the first F-bearing phases to crystallize at high pressure, whereas fluorite and topaz should crystallize first at low pressure. Following reaction models the saturation of fluorite and topaz: CaAl2Si2O8 (plagioclase) + 2[AlF3]melt = CaF2 (fluorite) + 2Al2SiO4F2 (topaz). The obtained partition coefficient for F between biotite and glass D(F)Bt/glass ranges from 1.89 to 0.80 (average value 1.29) and can be used as an empirical fluormeter to determine the F content of coexisting melts. Combined petrological and experimental studies of the Kymi equigranular topaz granite indicate that plagioclase was the liquidus phase at nearly water-saturated (fluid-saturated) conditions and that the F content of the melt was at least 2 wt%. The mean F content of natural biotite (3.92 wt%) suggests that the late-stage crystallization of biotite occurred in melts containing about 3 wt% F. The early crystallization of biotite and the presence of muscovite in our experiments at 200 MPa contrasts with the late-stage crystallization of biotite and the absence of muscovite in the natural assemblage, indicating that crystallization pressure may have been lower than 200 MPa for the granite. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.  相似文献   

16.
赣东南含黄玉花岗质岩石的成因探讨   总被引:3,自引:0,他引:3  
本文讨论了出露于赣东南石城、寻乌等地燕山期含黄玉岩浆岩的主要岩石组合及其成矿关系.根据黄玉的结晶习性,提出有部分黄玉是在岩浆晚期至岩浆期后气相阶段结晶的.根据本区含黄玉岩石为强过铝质(ANKC=1.108~28.806),高 F/Cl 比(53~1000)和 Rb/Sr 比(41~176),高的 l_(Sr)(T)(0.7129~0.7308)和低的ε_(Nd)(T)(-5.93~-7.11)值,认为在成因上应属 S-型分异的,而非 A-型.  相似文献   

17.
Textural and geochemical studies of inclusions in topaz from greisens in the Hensbarrow topaz granite stock (St. Austell, Cornwall) are used to constrain the composition of fluids responsible for late stage greisening and mineralisation. The topaz contains an abundant and varied suite of inclusions including aqueous liquid + vapour (L + V), quartz, zinnwaldite, albite, K-feldspar, muscovite, ilmenorutile, apatite, columbite, zircon, varlamoffite [(Sn, Fe)(O, OH)2] and qitianlingite [(Fe+2,Mn+2)2(Nb,Ta)2W+6O10]. Primary L + V inclusions in topaz show relatively high T h (mainly 300 to >500 °C) and a narrow range of salinities (23–30 wt % NaCl equivalent) compared with those in greisen quartz (150–450 °C, 0–50 wt % NaCl equivalent). Textures indicate that topaz formed earlier than quartz and the fluid inclusion data are interpreted as indicating a cooling of the hydrothermal fluids during greisenisation, mixing with meteoric waters and a decrease in pressure causing intermittent boiling. The presence of early-formed albite and K-feldspar as inclusions in the topaz is likely to indicate that the greisen-forming fluid became progressively more acid during greisenisation. The most distinctive inclusions in the topaz are wisp- and bleb-shaped quartz, < 50 μm in size, which show textural characteristics indicating former high degrees of plasticity. They often have multiple shrinkage bubbles at their margins rich in Sn, Fe, Mn, S and Cl and, more rarely, contain euhedral albite, K-feldspar, stannite or pyrrhotite crystals up to 40 μm in size. The quartz inclusions show similar morphologies to inclusions in topaz from quartz-topaz rocks elsewhere which have been interpreted as trapped “silicate melt”. Their compositions are, however, very different to those expected for late stage topaz-normative granitic melts. From their textural and chemical characteristics they are interpreted as representing crystallised silica colloid, probably trapped as a hydro gel during greisenisation. There is also evidence for the colloidal origin of inclusions of varlamoffite in the topaz. These occurrences offer the first reported evidence in natural systems for the formation of colloids in high temperature hydrothermal fluids. Their high ore carrying potential is suggested by the presence of varlamoffite and the occurrence of stannite, pyrrhotite and SnCl within the quartz inclusions. Received: 9 April 1996 / Accepted: 12 November 1996  相似文献   

18.
黄玉改色试验及呈色机理研究   总被引:2,自引:0,他引:2  
季金华  蔡述伟 《江苏地质》2000,24(3):153-156
采用高能射线辐照无色黄玉使其改色,并对呈色机理作了探讨。无色黄玉改色为天蓝-海蓝色后,颜色稳定,改为棕黄色的则在强阳光下易退色。  相似文献   

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