我国发现的钇硅磷灰石

我国首次发现的钇硅磷灰石产于河南含稀有金属的花岗岩内,为磷灰石型结构的硅酸盐矿物。乳白、玫瑰、棕色,实测比重4.35,一轴负晶,ω=1.784,ε=1.991。探针分析计算化学式为:(Y_(3.17)Ca_(1.56)Dy_(0.22)…)[(Si_(0.92)P_(0.03))O_4]_3(OH,F),P6_3/m,α=9.426±0.008,c=6.806±0.007。还进行了X射线粉晶衍射分析和红外吸收光谱分析,最后对具磷灰石型结构矿物种间阳离子、阴离子、附加阴离子之间的置换方式进行了讨论。     

我国羟硅铈矿的发现与矿物学特征

本文研究的羟硅铈矿是国内首次发现的该种矿物,产于河南太平镇稀土矿的破碎带蚀变岩中,与铈褐帘石、gatelite-(Ce)、富氟硅铈石、氟碳铈矿、直氟碳钙铈矿、氟铈矿、氟镧矿等稀土矿物紧密共生,多呈铈褐帘石假象细粒状集合体或与gatelite-(Ce)平行交生沿外围交代铈褐帘石产出,粒径一般小于0.1 mm,为自形-半自形,粒状-板状。该矿物呈浅绿色至橄榄绿色,透明,玻璃光泽,不规则断口,摩氏硬度约为4.5,计算密度5.08 g/cm3。光学性质:二轴晶,正光性,多色性明显,单偏光下呈绿色,正交偏光下具有鲜艳的高级干涉色。电子探针分析显示,矿物成分w(Ce_2O_3) 32.05%～34.26%,w(La_2O_3) 13.67%～17.66%,w(Pr_2O_3) 2.92%～3.68%,w(Nd_2O_3) 7.52%～10.34%,w(Al_2O_3) 8.59%～10.93%,w(SiO_2) 21.35%～24.97%,按照Si+P=2(apfu)计算单位分子式中阳离子数,OH+F=1(apfu)计算单位分子式中羟基的离子数,得出该矿物的经验化学式为(Ce1.02La0.49Nd0.27Pr0.10 Sm0.02Gd0.01Th0.01Mg0.06 Ca0.01)Σ2.00 (Al0.99Fe0.03)Σ1.02(SiO4)Σ2.00(OH0.81F0.19)Σ1.00。X射线单晶衍射分析表明,该矿物属于单斜晶系,晶胞参数:a=7.4382(3)?, b=5.6730(2)?, c=16.9819(8)?,β=118.84(0)°, Z=4, V=655.13(5)?3,空间群为P21/c。矿物的激光拉曼光谱特征峰主要为241、362,862、895、954和3722cm-1等,上述特征均与国外已发表的羟硅铈矿数据非常相似,是对羟硅铈矿分子振动光谱特征的首次探索。本文还对羟硅铈矿的矿物族归属以及矿物成因进行了初步的探讨。     

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

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.     

氟钠烧绿石——一种烧绿石超族的新矿物

氟钠烧绿石发现于中国新疆维吾尔自治区阿克苏地区波孜果尔稀土矿床的碱性侵入花岗岩中。本文对其物理性质、化学成分和晶体结构进行了研究,并按照烧绿石超族矿物分类命名新方案定名为"氟钠烧绿石"。该新矿物及其名称得到了国际矿物学会新矿物及矿物、分类命名委员会(CNMNC-IMA)的正式批准。     

新矿物—赤路矿的发现和研究

赤路矿(chiluite),是一种含铋、碲、钼、氧的新矿物,化学分子式是Bi_6Te_2Mo_2O_(21)。 赤路矿产在辉铋矿石英脉中,与硫碲铋矿、辉钼矿、钼铋矿共生,常呈羽毛状或不规则粒状,有时可见六边形晶体,粒度一般<30μm,反光显微镜下呈灰色,弱非均质,反射率560nm,R′g 18.10％,R′p 17.15％,透射光下褐色,一轴晶负光性,折光率ω=2.4,ε=2.3,硬度3.2,比重3.65。X射线粉晶分析,赤路矿属六方晶系,主要线条:d_(meas)A(I)(hkl)是3.300(10)(004),3.050(9)(104),2.510(5)(105),2.060(5)(312),1.655(5)(008)。电子探针分析结果,Bi61.66,Te11.19,Mo10.29,O16.06。 在400-900℃条件下合成了赤路矿的同质多象晶体,并进行了红外光谱,差热分析及电子能谱测定元素价态等研究工作。     

基于透钙磷石向磷灰石转化的除氟过程及其机理

磷灰石的沉淀可以影响矿物相-水相之间氟化物的分配,在饮用水除氟以及延缓土壤中氟的迁移过程中扮演着重要角色。本研究通过共沉淀法制备了磷灰石的前驱体矿物透钙磷石,并将其转化为溶解度更低的磷灰石,以研究其转化过程中矿物相的演变及对氟的固定能力,并探讨了氟的固定机理。结果表明,溶液中的氟伴随着磷灰石的沉淀由液相转移至固相中,此过程对氟的固定量高达21.8 mg/g,是羟基磷灰石对氟吸附量的2.2倍。透钙磷石转化为磷灰石的过程为溶解-沉淀过程,氟在磷灰石的生长过程中进入磷灰石的结构中。此外,透钙磷石向磷灰石的转化过程对氟的去除具有高度选择性,溶液中共存的Cl^-、CO₃^2-、NO₃^-和SO₄^2-等阴离子几乎不影响其氟去除能力。研究结果表明,通过透钙磷石-磷灰石的转化可以将氟固定到磷灰石中,从而降低氟的可迁移性和渗入地下水造成的环境风险。     

新矿物—彭志忠石的发现及研究

彭志忠石产于湖南安化白钨矿区,是一种富含镁、锡、铝的复杂氧化物。矿物为浅黄褐色、浅黄色,少量无色,晶体呈六方板状。晶体化学式为:(Mg,Zn,Fe,Al)_4(Sn,Fe)_2(Al,□)_(10)O_(22)(OH)_2,空间群P_3ml,a=5.692(5)A,c=13.78(2)A,V=386.7A~3,Z=1。D=4.22(3)g/cm~3,H≥8,一轴正晶,ω=1.802(2),ε=1.814(2)。     

一种硼酸盐的新矿物—袁复礼石

袁复礼石是一种Mg、Fe2+、Al和Ti的硼酸盐新矿物，发现于辽宁省宽甸县砖庙硼矿区。该矿物黑色，近不透明，金刚光泽-半金属光泽。反射色亮灰，内反射深红褐色。非均质性弱，偏光色红褐。晶体呈细柱状，O.1×0.2×l mm。晶体化学式为:(Mg0.91Fe2+0.09)(Fe3+0.56Al3+0.19 Mg0.17Ti0.11Fe2+0.10)1.13(B0.92O3.00)O。空间群Pnam, a=9.258(6)A，b=9.351(4)A， c=3.081(2)A，V=266.80(2)A，Z=4。 D=3.80 g/cm3, H=5-6，VHN50=843 kg/mm2，｛100}解理完全。红外光谱吸收谱带为:1387, 1210, 1024, 951, 733, 600, 510和408 cm-1。穆斯堡尔谱证明，以三价铁为主，二价铁较少。Fe3+占据M(1)晶位，Fe2+占据M(1)和M(2)晶位。袁复礼石为硼钛镁石的富Fe3+类似物。     

Petrogenesis of the gabbros from Mt. St. Hilaire,Quebec, Canada

Mt. St. Hilaire occurs as a small funnel-shaped intrusion in the Monteregian petrographic province of Quebec and consists of alkali gabbros and later nepheline syenites. Based on field relations, petrography, and geochemistry, five types of gabbro are recognized. In order of intrusion these are: leucogabbro, foliated gabbro, kaersutite-biotite gabbro, kaersutite gabbro, and a gabbro-melagabbro series. Based on analyses of the early-forming ilmenite-titanomagnetite, the gabbros crystallized under high fO₂ conditions which lead to subsequent crystallization of olivines with high MnO contents. Fractionation of ilmenite and titanomagnetite was a major control on the Ti and A[TV]concentrations in the clinopyroxenes. Plagioclase compositions in the gabbros became richer in Ab contents in the sequence gabbro-melagabbro to leucogabbro. Whole-rock analyses suggest that the parental magma of alkali basaltic composition was fairly evolved prior to emplacement. Lack of olivine in the cumulate gabbro-melagabbros and low Ni and Cr in all gabbros may reflect either extreme olivine fractionation and/or a very low olivine content in the source material for these basalts. Differentiation of the gabbros occurred both pre- and post-emplacement, probably by a process of crystal-liquid fractionation at depths between 3-5 and 8 km. This is in accordance with geophysical measurements for other Monteregian intrusions. A model is presented for the mechanism of emplacement.     

氟碳铈矿和氟铈矿晶体结构的精确测定

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．     

Linking groundwater quality to residence times and regional geology in the St. Lawrence Lowlands,southern Quebec,Canada

The assessment of groundwater quality in shallow aquifers is of high societal relevance given that large populations depend directly on these water resources. The purpose of this study was to establish links between groundwater quality, groundwater residence times, and regional geology in the St. Lawrence Lowlands fractured bedrock aquifer. The study focuses on a 4500 km² watershed located in the St. Lawrence Lowlands of the province of Quebec in eastern Canada. A total of 150 wells were sampled for major, minor, and trace ions. Tritium (³H) and its daughter element, ³He, as well as radiocarbon activity (A¹⁴C) were measured in a subset of wells to estimate groundwater residence times. Results show that groundwater evolves from a Ca–HCO₃ water type in recharge zones (i.e., the Appalachian piedmont) to a Na–HCO₃ water type downgradient, toward the St. Lawrence River. Locally, barium (Ba), fluoride (F), iron (Fe), and manganese (Mn) concentrations reach 90, 2, 18, and 5.9 mg/L respectively, all exceeding their respective Canadian drinking water limits of 1, 1.5, 0.3, and 0.05 mg/L. Release of these elements into groundwater is mainly controlled by the groundwater redox state and pH conditions, as well as by the geology and the duration of rock–water interactions. This evolution is accompanied by increasing ³H/³He ages, from 4.78 ± 0.44 years upgradient to more than 60 years downgradient. Discrepancies between calculated ³H/³He and ¹⁴C water ages (the latter ranging from 280 ± 56 to 17,050 ± 3410 years) suggest mixing between modern water and paleo-groundwater infiltrated through subglacial recharge when the Laurentide Ice Sheet covered the study area, and during the following deglaciation period. A linear relationship between ³H activity and corrected ¹⁴C versus Mg/Ca and Ba support a direct link between water residence time and the chemical evolution of these waters. The Ba, F, Fe, and Mn concentrations in groundwater originate from Paleozoic rocks from both the St. Lawrence Platform and the Appalachian Mountains. These elements have been brought to the surface by rising hydrothermal fluids along regional faults, and trapped in sediment during their deposition and diagenesis due to reactions with highly sulfurous and organic matter-rich water. Large-scale flow of meltwater during subglacial recharge and during the subsequent retreat of the Laurentide Ice Sheet might have contributed to the leaching of these deposits and their enrichment in the present aquifers. This study brings a new and original understanding of the St. Lawrence Lowlands groundwater system within the context of its geological evolution.     

对于氟碳钡铈矿（Cordylite—Ce）成分与结构的质疑

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。     

独居石和磷钇矿晶体结构的精确测定

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。     

黄河矿的一种特殊双晶的发现及其倒易点阵特征

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。     

Titanium,Ti, A New Mineral Species from Luobusha,Tibet, China

We describe the new mineral species titanium,ideally Ti,found in the podiform chromitites of the Luobusha ophiolite in Tibet,People’s Republic of China.The irregular crystals range from 0.1 to 0.6 mm in diameter and form an intergrowth with coesite and kyanite.Titanium is silver grey in colour,the luster is metallic,it is opaque,the streak is grayish black,and it is non-fluorescent.The mineral is malleable,has a rough to hackly fracture and has no apparent cleavage.The estimated Mohs hardness is 4,and the calculated density is 4.503 g/cm3.The composition is Ti 99.23-100.00 wt%.The mineral is hexagonal,space group P63 /mmc.Unit-cell parameters are a 2.950(2),c 4.686(1),V 35.32(5) 3,Z = 2.The five strongest powder diffraction lines [d in(hkl)(I/I0)] are: 2.569(010)(32),2.254(011)(100),1.730(012)(16),1.478(110)(21),and 0.9464(121)(8).The species and name were approved by the CNMNC(IMA 2010–044).     

白云鄂博矿的电子衍射和结构象研究

用电子衍射和高分辩电子显微术研究了白云鄂博矿。沿[100]方向拍摄了晶体的结构象。依此,肯定了X射线结构分析的结果。     

白云鄂博矿的晶体结构

在矿物学研究的基础上,对白云鄂博矿进行了X射线晶体结构测定。经四圆衍射仪精测了该矿物的晶胞参数,收集和处理其衍射强度数据。用帕特逊函数法给出Ba、Ce原子的粗略位置,在对其精修后,用差值电子密度函数法求得Na、F及CO_3的坐标,最终R=0.049。本文对其晶体结构特征作了详细研究,依此满意地解释了该矿物的主要物性、光性和红外光谱特征。