我国羟硅铈矿的发现与矿物学特征
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摘要
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。
The t?rnebohmite-(Ce), which was discovered in China for the first time, occurred in altered rocks in fracture zones of the Taipingzhen REE deposit, Henan Province. It is closely associated with other REE minerals including allanite-(Ce), gatelite-(Ce), F-rich cerite-(Ce), bastn?esite-(Ce), synchysite-(Ce), fluocerite-(La), and fluocerite-(Ce) in forms of intergrowth. It mostly occurred as fine-grained aggregates in form of allanite-(Ce) pseudomorph, or as the t?rnebohmite-gatelite-(Ce) intergrowth which replaced marginal parts of allanite-(Ce) crystals. It has euhedral-subhedral,granular-tabular crystals with size of generally less than 0.1 mm. It is transparent. It has light green to olive green color,glass luster, irregular fracture, Mohs' hardness of about 4.5, with calculated density of 5.08 g/cm~3. It has optical properties of biaxial crystal, optically positive, strong polychromatism, green color under single polarized light, with bright high-level interference color under crossed nicols. Its chemical compositions analyzed using EPMA(with 10 analytical points in 2 grains) are of 32.05%-34.26% Ce_2O_3, 13.67%-17.66% La_2O_3, 2.92%-3.68% Pr2 O3, 7.52%-10.34% Nd_2O_3,8.59%-10.93% Al_2O_3, and 21.35%-24.97% SiO_2. According to the equation of Si+P=2 to calculate the number of cations,and the equation of OH+F=1 to calculate the number of anions, its empirical formula is(Ce1.02 La0.49 Nd0.27 Pr0.10 Sm0.02 Gd0.01 Th0.01 Mg0.06 Ca0.01)Σ2.00(Al0.99 Fe0.03)Σ1.02(SiO4) Σ2.00(OH0.81 F0.19)Σ1.00.On the basis of the analysis of X-ray single crystal diffraction, the t?rnebohmite-(Ce) belongs to monoclinic system, with the unit cell parameters of a=7.4382(3)?, b= 5.6730(2)?, c= 16.9819(8)?; β=118.84(0)°, Z=4, V= 655.13(5)?3, and the space group of P21/c,respectively. Furthermore, characteristic peaks of the laser Raman spectral were observed at 241, 362, 862, 895, 954, 3722 cm-1, respectively. All those features of t?rnebohmite-(Ce) from the Taipingzhen are very similar to those of the reported t?rnebohmite-(Ce) in abroad. This is the first exploration for the molecular vibrational characteristics of t?rnebohmite-(Ce)from the Taipingzhen REE deposit. The genesis and affiliation of t?rnebohmite-(Ce) have also been basically discussed in this paper.
The t?rnebohmite-(Ce), which was discovered in China for the first time, occurred in altered rocks in fracture zones of the Taipingzhen REE deposit, Henan Province. It is closely associated with other REE minerals including allanite-(Ce), gatelite-(Ce), F-rich cerite-(Ce), bastn?esite-(Ce), synchysite-(Ce), fluocerite-(La), and fluocerite-(Ce) in forms of intergrowth. It mostly occurred as fine-grained aggregates in form of allanite-(Ce) pseudomorph, or as the t?rnebohmite-gatelite-(Ce) intergrowth which replaced marginal parts of allanite-(Ce) crystals. It has euhedral-subhedral,granular-tabular crystals with size of generally less than 0.1 mm. It is transparent. It has light green to olive green color,glass luster, irregular fracture, Mohs' hardness of about 4.5, with calculated density of 5.08 g/cm~3. It has optical properties of biaxial crystal, optically positive, strong polychromatism, green color under single polarized light, with bright high-level interference color under crossed nicols. Its chemical compositions analyzed using EPMA(with 10 analytical points in 2 grains) are of 32.05%-34.26% Ce_2O_3, 13.67%-17.66% La_2O_3, 2.92%-3.68% Pr2 O3, 7.52%-10.34% Nd_2O_3,8.59%-10.93% Al_2O_3, and 21.35%-24.97% SiO_2. According to the equation of Si+P=2 to calculate the number of cations,and the equation of OH+F=1 to calculate the number of anions, its empirical formula is(Ce1.02 La0.49 Nd0.27 Pr0.10 Sm0.02 Gd0.01 Th0.01 Mg0.06 Ca0.01)Σ2.00(Al0.99 Fe0.03)Σ1.02(SiO4) Σ2.00(OH0.81 F0.19)Σ1.00.On the basis of the analysis of X-ray single crystal diffraction, the t?rnebohmite-(Ce) belongs to monoclinic system, with the unit cell parameters of a=7.4382(3)?, b= 5.6730(2)?, c= 16.9819(8)?; β=118.84(0)°, Z=4, V= 655.13(5)?3, and the space group of P21/c,respectively. Furthermore, characteristic peaks of the laser Raman spectral were observed at 241, 362, 862, 895, 954, 3722 cm-1, respectively. All those features of t?rnebohmite-(Ce) from the Taipingzhen are very similar to those of the reported t?rnebohmite-(Ce) in abroad. This is the first exploration for the molecular vibrational characteristics of t?rnebohmite-(Ce)from the Taipingzhen REE deposit. The genesis and affiliation of t?rnebohmite-(Ce) have also been basically discussed in this paper.
引文
[1]Geijer P.The cerium minerals of Bastn?s at Riddarhyttan[J].Sveriges Geologiska Unders?kning Arsbok,1921,14(6):3-24.
[2]Levinson A.A system of nomenclature for rare-earth minerals[J].American Mineralogist,1966,51(1/2):152-158.
[3]Bayliss P,Levinson A A.A system of nomenclature for rare-earth mineral species:revision and extension[J].American Mineralogist,1988,73(3/4):422-423.
[4]Holtstam D,Andersson U B.The REE minerals of the Bastn?s-type deposits,South-Central Sweden[J].The Canadian Mineralogist.2007,45:1073-1114.
[5]Gonnard E N,Glass J J.Deposits of radioactive cerite near Jamestown,Colorado[J].American Mineralogist,1940,25(6):381-404.
[6]Sviajin N V.T?rnebohmite from the alkaline province of Ural[J].Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva,1962,91:97-99.
[7]Kapustin Y L.Cerite and t?rnebohmite from fenites in the alkaline Tuva massifs[J].in Russian.Zap Vses.Mineral Obshchest,1989,118(4):47-56.
[8]Chaudhuri J N B,Newesely H.On the REE-bearing minerals in the beach placers of Puri,Orissa District[J].Journal of Southeast Asian Earth Sciences,1993,8(1/2/3/4):287-291.
[9]F?rster H J.Cerite-(Ce)and thorian synchysite-(Ce)from the Niederbobritzsch granite,Erzgebirge,Germany:implications for the differential mobility of the LREE and Th during alteration[J].The Canadian Mineralogist,2000,38(1):67-79.
[10]Husdal T A.The minerals of the pegmatites within the Tysfjord granite,northern Norway[J].Norsk Bergverksmuseum Skrift,2008,38(1):5-28.
[11]Mills S J,Kartashov P M,Kampf A R,et al.Cordylite-(La),A New Mineral Species In Fenite From The Biraya Fe-Ree Deposit,Irkutsk,Russia[J].The Canadian Mineralogist,2012,50(5):1281-1290.
[12]Hirtopanu P,Andersen J C,Fairhurst R J,et al.Allanite-(Ce)and its associations,from the Ditrau alkaline intrusive massif,East Carpathians,Romania[J].Proceedings of the Romanian Academy,Series B,2013,15:59-74.
[13]Khomenko V M,Vyshnevskyy O A,Strekozov S N.T?rnebohmite and Gatelite of Anadol ore occurrence in the Azov area:the first finding in Ukraine[J].in Russian with English abstract.Mineral Journal(Ukraine),2013,35(4):32-43.
[14]Shen Jinchuan,Moore P B.T?rnebohmite,RE2Al(OH)[SiO4]2:crystal structure and genealogy of RE(III)Si(IV)?-?Ca(II)P(V)isomorphisms[J].American Mineralogist,1982,67(5):1021-1028.
[15]宓锦校,沈今川,梁军,等.羟硅铈矿晶体结构的精确修正[J].地质科技情报,1996,15(1):39-43.
[16]李靖辉,陈化凯,张宏伟,等.豫西太平镇轻稀土矿床矿化特征及矿床成因[J].中国地质,2017,44(2):288-300.
[17]Bonazzi P,Bindi L,Parodi G.Gatelite-(Ce).a new REE-bearing mineral from Trimouns,French Pyrenees:Crystal structure and polysomatic relation-ships with epidote and t?rnebohmite-(Ce)[J].American Mineralogist,2003,88(1):223-228.
[18]范光,于阿朋,葛祥坤,等.国内首次发现的束磷钙铀矿的矿物学特征[J].岩石矿物学杂志,2014,33(1):95-101.
[19]李国武,薛源,谢英美.新矿物碲钨矿的矿物学特征及成因探讨[J].矿物岩石地球化学通报,2018,37(2):186-191.
[20]Hermann J.Allanite:thorium and light rare earth element carrier in subducted crust[J].Chemical geology,2002,192(3/4):289-306.
[21]Qu K,Sima XZ,Zhou HY,et al.In situ LA-MC-ICP-MS and ID-TIMS U-Pb ages of bastn?site-(Ce)and zircon from the Taipingzhen hydrothermal REE deposit:New constraints on the Later Paleozoic granite-related U-REE mineralization in the North Qinling Orogen,Central China[J].Journal of Asian Earth Sciences,2019,173(5):352-363.
[22]王濮,潘兆橹,翁玲宝.系统矿物学(中)[M].北京:地质出版社,1982:207.
[23]Hisinger W,Berzelius J J.Cerium,en ny Metall,funnen i Bastn?s Tungsten fr?n Riddarhyttan i Westmanland[M].Stockholm:Nordstr?m,1804.
[24]Pakhomovsky Y A,Men'Shikov Y P,Yakovenchuk V N,et al.Cerite-(La),(La,Ce,Ca)9(Fe,Ca,Mg)(SiO4)3[SiO3(OH)]4(OH)3,a new mineral species from the khibina alkaline massif:occurrence and crystal structure[J].The The Canadian Mineralogist,2002,40(4):1177-1184.
[25]Nestola F,Guastoni A,Cámara F,et al.Aluminocerite-Ce:A new species from Baveno,Italy:Description and crystal-structure determination[J].American Mineralogist,2009,94(4):487-493.
[26]Armbruster T,Bonazzi P,Akasaka M,et al.Recommended nomenclature of epidote-group minerals[J].European Journal of Mineralogy,2006,18(5):551-567.
[27]H?lenius U,Hatert F,Pasero M,et al.IMA Commission on New Minerals,Nomenclature and Classification(CNMNC)[J].Mineralogical Magazine,2017,29:1083-1087.
[28]Bonazzi P,Holtstam D,Bindi L.Gatelite-supergroup minerals:recommended nomenclature and review[J].European Journal of Mineralogy,2019,31(1):173-181.
[29]曲凯,司马献章,李国武,等.我国首次发现的氟镧矿的矿物学研究[J/OL].矿物岩石地球化学通报,2019,38://doi.org/10.19658/j.issn.1007-2802.2019.38.040.
[2]Levinson A.A system of nomenclature for rare-earth minerals[J].American Mineralogist,1966,51(1/2):152-158.
[3]Bayliss P,Levinson A A.A system of nomenclature for rare-earth mineral species:revision and extension[J].American Mineralogist,1988,73(3/4):422-423.
[4]Holtstam D,Andersson U B.The REE minerals of the Bastn?s-type deposits,South-Central Sweden[J].The Canadian Mineralogist.2007,45:1073-1114.
[5]Gonnard E N,Glass J J.Deposits of radioactive cerite near Jamestown,Colorado[J].American Mineralogist,1940,25(6):381-404.
[6]Sviajin N V.T?rnebohmite from the alkaline province of Ural[J].Zapiski Vsesoyuznogo Mineralogicheskogo Obshchestva,1962,91:97-99.
[7]Kapustin Y L.Cerite and t?rnebohmite from fenites in the alkaline Tuva massifs[J].in Russian.Zap Vses.Mineral Obshchest,1989,118(4):47-56.
[8]Chaudhuri J N B,Newesely H.On the REE-bearing minerals in the beach placers of Puri,Orissa District[J].Journal of Southeast Asian Earth Sciences,1993,8(1/2/3/4):287-291.
[9]F?rster H J.Cerite-(Ce)and thorian synchysite-(Ce)from the Niederbobritzsch granite,Erzgebirge,Germany:implications for the differential mobility of the LREE and Th during alteration[J].The Canadian Mineralogist,2000,38(1):67-79.
[10]Husdal T A.The minerals of the pegmatites within the Tysfjord granite,northern Norway[J].Norsk Bergverksmuseum Skrift,2008,38(1):5-28.
[11]Mills S J,Kartashov P M,Kampf A R,et al.Cordylite-(La),A New Mineral Species In Fenite From The Biraya Fe-Ree Deposit,Irkutsk,Russia[J].The Canadian Mineralogist,2012,50(5):1281-1290.
[12]Hirtopanu P,Andersen J C,Fairhurst R J,et al.Allanite-(Ce)and its associations,from the Ditrau alkaline intrusive massif,East Carpathians,Romania[J].Proceedings of the Romanian Academy,Series B,2013,15:59-74.
[13]Khomenko V M,Vyshnevskyy O A,Strekozov S N.T?rnebohmite and Gatelite of Anadol ore occurrence in the Azov area:the first finding in Ukraine[J].in Russian with English abstract.Mineral Journal(Ukraine),2013,35(4):32-43.
[14]Shen Jinchuan,Moore P B.T?rnebohmite,RE2Al(OH)[SiO4]2:crystal structure and genealogy of RE(III)Si(IV)?-?Ca(II)P(V)isomorphisms[J].American Mineralogist,1982,67(5):1021-1028.
[15]宓锦校,沈今川,梁军,等.羟硅铈矿晶体结构的精确修正[J].地质科技情报,1996,15(1):39-43.
[16]李靖辉,陈化凯,张宏伟,等.豫西太平镇轻稀土矿床矿化特征及矿床成因[J].中国地质,2017,44(2):288-300.
[17]Bonazzi P,Bindi L,Parodi G.Gatelite-(Ce).a new REE-bearing mineral from Trimouns,French Pyrenees:Crystal structure and polysomatic relation-ships with epidote and t?rnebohmite-(Ce)[J].American Mineralogist,2003,88(1):223-228.
[18]范光,于阿朋,葛祥坤,等.国内首次发现的束磷钙铀矿的矿物学特征[J].岩石矿物学杂志,2014,33(1):95-101.
[19]李国武,薛源,谢英美.新矿物碲钨矿的矿物学特征及成因探讨[J].矿物岩石地球化学通报,2018,37(2):186-191.
[20]Hermann J.Allanite:thorium and light rare earth element carrier in subducted crust[J].Chemical geology,2002,192(3/4):289-306.
[21]Qu K,Sima XZ,Zhou HY,et al.In situ LA-MC-ICP-MS and ID-TIMS U-Pb ages of bastn?site-(Ce)and zircon from the Taipingzhen hydrothermal REE deposit:New constraints on the Later Paleozoic granite-related U-REE mineralization in the North Qinling Orogen,Central China[J].Journal of Asian Earth Sciences,2019,173(5):352-363.
[22]王濮,潘兆橹,翁玲宝.系统矿物学(中)[M].北京:地质出版社,1982:207.
[23]Hisinger W,Berzelius J J.Cerium,en ny Metall,funnen i Bastn?s Tungsten fr?n Riddarhyttan i Westmanland[M].Stockholm:Nordstr?m,1804.
[24]Pakhomovsky Y A,Men'Shikov Y P,Yakovenchuk V N,et al.Cerite-(La),(La,Ce,Ca)9(Fe,Ca,Mg)(SiO4)3[SiO3(OH)]4(OH)3,a new mineral species from the khibina alkaline massif:occurrence and crystal structure[J].The The Canadian Mineralogist,2002,40(4):1177-1184.
[25]Nestola F,Guastoni A,Cámara F,et al.Aluminocerite-Ce:A new species from Baveno,Italy:Description and crystal-structure determination[J].American Mineralogist,2009,94(4):487-493.
[26]Armbruster T,Bonazzi P,Akasaka M,et al.Recommended nomenclature of epidote-group minerals[J].European Journal of Mineralogy,2006,18(5):551-567.
[27]H?lenius U,Hatert F,Pasero M,et al.IMA Commission on New Minerals,Nomenclature and Classification(CNMNC)[J].Mineralogical Magazine,2017,29:1083-1087.
[28]Bonazzi P,Holtstam D,Bindi L.Gatelite-supergroup minerals:recommended nomenclature and review[J].European Journal of Mineralogy,2019,31(1):173-181.
[29]曲凯,司马献章,李国武,等.我国首次发现的氟镧矿的矿物学研究[J/OL].矿物岩石地球化学通报,2019,38://doi.org/10.19658/j.issn.1007-2802.2019.38.040.