摘要 氟碳钡铈矿(Cordylite)BaCe2(CO3)3 F2本世纪初首先发现于格陵兰纳尔萨尔苏克(Narssarssuk)的碱性正长伟晶岩脉中,与霓石、氟碳铈钙矿、柱星叶石和碳锶铈矿共生。1965年该矿物又发现于我国白云鄂博西矿区热液交代的元古代白云岩中。1975年,加拿大魁北克省圣赫莱山(Mont st. Hilaire,Quebec)的霞石正长岩中的伟晶岩脉中也发现了这一矿物,它与方沸石、霓石和钠闪石共生。
In Bayun-Obo, cordylite with associated parisite and barite forms massive aggregates. Under polarizing microscope, cordylite is traslucent and colorless or light yellowish in thin section. It has no cleavage and has irregular fractures. Its optics is uniaxial, negative. The indices of refraction are N0=1.760, Ne=1.585, N0-Ne=0.175. Mohs hardness is about 4.5. X-Ray powder diffraction pattern of eordylite is obtained and well identical with that from Greenland. Cordylite is hexagonal and the parameters of unit cell are σ0= 5.081, C0=23.10Å, C0/a0=4.547, v0=514.39Å3.Cordylite can be solved in acids. The chemical composition and the concentrations of rare-earth elements of cordylite are also obtained by wet chemical analysis. It is shown that the predominate rare earth elements are cerium, neodymium, lanthanum and praseodymium.A very interesting fact is that cordylite is closely associated with parisite, it is difficult to separate them. It is assumed that during rare earth mineralization, barium and calcium formed their own minerals respectively.It is evident that the cordylite of Bayun-Obo contains certain amount of sodium. Therefore, the crystallochemistry of sodium in cordylite of Bayun-Obo should be further studied.
张培善,陶克捷. 1985, 白云鄂博的氟碳钡铈矿. 地质科学, (2): 191-195.
Zhang Peishan,Tao Kejie. CORDYLITE IN BAYUN-OBO[J]. Chinese Journal of Geology, 1985, (2): 191-195.