Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-23T17:50:13.608Z Has data issue: false hasContentIssue false
  • English
  • Français

Arisite-(La), a new REE-fluorcarbonate mineral from the Aris phonolite (Namibia), with descriptions of the crystal structures of arisite-(La) and arisite-(Ce)

Published online by Cambridge University Press:  05 July 2018

P. C. Piilonen ,
A. M. McDonald ,
J. D. Grice ,
M. A. Cooper ,
U. Kolitsch ,
R. Rowe ,
R. A. Gault  and
G. Poirier
P. C. Piilonen*
Affiliation:
Research Division, Canadian Museum of Nature, Ottawa, Ontario K1P 6P, Canada
A. M. McDonald
Affiliation:
Department of Earth Sciences, Laurentian University, Sudbury, Ontario P3E 2C6, Canada
J. D. Grice
Affiliation:
Research Division, Canadian Museum of Nature, Ottawa, Ontario K1P 6P, Canada
M. A. Cooper
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
U. Kolitsch
Affiliation:
Mineralogisch-Petrographische Abt., Naturhistorisches Museum, Burgring 7, A-1010 Wien, Austria
R. Rowe
Affiliation:
Research Division, Canadian Museum of Nature, Ottawa, Ontario K1P 6P, Canada
R. A. Gault
Affiliation:
Research Division, Canadian Museum of Nature, Ottawa, Ontario K1P 6P, Canada
G. Poirier
Affiliation:
Research Division, Canadian Museum of Nature, Ottawa, Ontario K1P 6P, Canada
*
*E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Arisite-(La), ideally NaLa2(CO3)2[F2x(CO3)1–x]F, is a new layered REE-fluorcarbonate mineral from miarolitic cavities within the Aris phonolite, Namibia (IMA no. 2009-019). It occurs as distinct chemical zones mixed with its Ce-analogue, arisite-(Ce). Crystals are vitreous, transparent beige, beige-yellow, light lemon-yellow to pinkish, and occur as tabular prisms up to 1.5 mm. Arisite-(La) is brittle, has conchoidal fracture, poor cleavage perpendicular to (001), a Mohs hardness of ~3–3½, is not fluorescent in either long- or shortwave UV radiation, dissolves slowly in dilute HCl at room temperature and sinks in methylene iodide, Dcalc. = 4.072 g cm–3. Arisite-(La) is uniaxial negative, has sharp extinction, with both ω and ε exhibiting a range of values within each grain: ω = 1.696–1.717(4) and ε = 1.594–1.611(3), a result of chemical zoning attributed to both Ce ⇌ La and Na ⇌ Ca substitutions. The crystal structure of both arisite-(Ce) and arisite-(La) were solved by direct methods and refined to R = 1.66%, wR2 = 4.31% (Ce) and R = 2.09%, wR2 = 5.26% (La), respectively. Arisite is hexagonal, Pm2, Z = 1, with unit-cell parameters of a = 5.1109(2) Å, c = 8.6713(4) Å, V = 196.16(6) Å3 for arisite-(Ce), and a = 5.1131(7) Å, c = 8.6759(17) Å, V = 196.43(5) Å3 for arisite-(La). Arisite-(Ce) and arisite-(La) are members of the layered, flat-lying REE-fluorcarbonate group which have crystal structures characterized by separate layers of triangular planar groups that parallel the overall layering of the structure, F, REE and alkali or alkaline-earthelements. Overall, the arisite structure can be defined by three distinct layers which parallel (001): (1) ∞[REE(CO3)2F] slabs, (2) sheets of Naϕ9 polyhedra, and (3) ∞[2F/CO3]2–. Based on its (M+F)/C ratio, arisite can further be described as having a dense, flat-lying fluorcarbonate structure, a classification which includes the structurally related mineral species cordylite, kukharenkoite, cebaite, lukechangite, huanghoite, and one incompletely characterized synthetic phase, NaY2(CO3)3F.

Keywords

fluorcarbonateREEAris phonolitestructure determinationnew mineral species
Type
Research Article
Information
Mineralogical Magazine , Volume 74 , Issue 2 , April 2010 , pp. 257 - 268
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Brese, N.E. and O'Keefe, M. (1991) Bond-valence parameters for solids. Ada Crystallographica B, 47, 192–197.Google Scholar
Bruker, (1997) XPREP – Data preparation and Reciprocal Space Exploration. Bruker AXS Inc., Madison, Wisconsin, USA.Google Scholar
Cromer, D.T. and Liberman, D. (1970) Relativistic calculation of anomalous scattering factors for X-rays. Journal of Chemical Physics, 53, 1891–1898.CrossRefGoogle Scholar
Cromer, D.T. and Mann, J.B. (1968) X-ray scattering factors computed from numerical Hartree-Fock wave functions. Acta Crystallographica A, 24, 321–324.CrossRefGoogle Scholar
Fitch, F.J. and Miller, J.A. (1984) Dating Karoo igneous rocks by the conventional K-Ar and 40Ar/39Ar age spectrum methods. Pp. 247–266 in: Petrogenesis of the Volcanic Rocks of the Karoo Province (Erlank, J.A., editor). Special Publication 13, Geological Survey of South Africa.Google Scholar
Gevers, T.W. (1934) Alkali-rocks in the Auas Mountains, south of Windhoek, S.W.A. Transactions of the Geological Society of South Africa, 36, 77–88.Google Scholar
Giester, G., Ni, Y., Jarosch, D., Hughes, J.M., Rønsbo, J., Yang, Z. and Zemann, J. (1998) Cordylite-(Ce) A crystal chemical investigation of material from four localities, including type material. American Mineralogist, 83, 178–184.CrossRefGoogle Scholar
Grice, J.D. and Chao, G.Y. (1997) Lukechangite-(Ce), a new rare-earth-fluorocarbonate mineral from Mont Saint-Hilaire, Quebec. American Mineralogist, 82, 1255–1260.CrossRefGoogle Scholar
Grice, J.D., Maisonneuve, V. and Leblanc, M. (2007) Natural and synthetic fluoride carbonates. Chemical Reviews, 107, 114–132.CrossRefGoogle ScholarPubMed
Krivovichev, S.V., Filatov, S.K. and Zaitsev, A.N. (1998) The crystal structure of kukharenkoite-(Ce), Ba2REE(CO3)3F, and an interpretation based on cation-coordinated F tetrahedra. The Canadian Mineralogist, 36, 809–815.Google Scholar
Kröner, A. (1973) Comments on ‘Is the African Plate stationary’. Nature, Physical Science, 243, 29–30.CrossRefGoogle Scholar
LePage, Y. (1988) MISSYM 1.1 – a flexible new release. Journal of Applied Crystallography, 21, 983–984.CrossRefGoogle Scholar
Marsh, J.S. (1987) Evolution of a strongly differentiated suite of phonolites from the Klinghardt Mountains, Namibia. Lithos, 20, 41–58.CrossRefGoogle Scholar
McArdle, P. (2004) Oscail X - Windows Software for Crystallography and Molecular Modelling. NUI Galway, Ireland.Google Scholar
Mercier, N. and Leblanc, M. (1993 a) Crystal growth and structures of rare earth fluorocarbonates: I. Structures of BaSm(CO3)2F and Ba3La2(CO3)5F2: revision of the corresponding huanghoite and cebaite type structures. European Journal of Solid State and Inorganic Chemistry, 30, 195–205.Google Scholar
Mercier, N. and Leblanc, M. (1993 b) Crystal growth and structures of rare earth fluorocarbonates: II. Structures of zhonghaucerite Ba2Ce(CO3)F. Correlations between huanghoite, cebaite and zhonghaucerite type structures. European Journal of Solid State and Inorganic Chemistry, 30, 207–216.Google Scholar
Mercier, N. and Leblanc, M. (1993 c) Existence of 3d transition metal fluorocarbonates: synthesis, char-acterization of BaM(CO3)F2 (M = Mn,Cu) and crystal structure of BaCu(CO3)F2 . European Journal of Solid State and Inorganic Chemistry, 30, 217–225.Google Scholar
Nolze, G. and Kraus, W. (1998) PowderCell 2.0 for Windows. Powder Diffraction, 13, 256–259.Google Scholar
Piilonen, P.C., McDonald, A.M., Grice, J.D., Rowe, R., Gault, R.A., Poirier, G., Cooper, M.A., Kolitsch, U., Roberts, A.C., Lechner, W. and Palfi, A.G. (2010) Arisite-(Ce), a new rare-earth fluorcarbonate from the Aris phonolite (Namibia), Mont Saint-Hilaire and the Saint-Amable sill (Québec). The Canadian Mineralogist, (in press).CrossRefGoogle Scholar
Rowe, R. (2009) New statistical calibration approach for Bruker AXS D8 Discover micro diffractometer with Hi-Star detector using GADDS software. Powder Diffraction, 24, 263–271.CrossRefGoogle Scholar
Sheldrick, G.M. (1997) SHELX-97. Program for the refinement of crystal structures. University of Gottingen, Germany.Google Scholar
Sturla, M., Yakovenchuk, V.N. and Bonacina, E. (2005) Aris, Namibia: Geo-paragenesi e minerali. Micro, 55–80 (in Italian).Google Scholar
von Knorring, O. and Franke, W. (1987) A preliminary note on the mineralogy and geochemistry of the Aris phonolite, SWA/Namibia. Communications of the Geological Survey of South Africa/Namibia, 3, 61.Google Scholar
Yang, Z. (1995) Structure redetermination of natural cebaite-(Ce), Ba3Ce2(CO3)5F2, Neues Jahrbuch für Mineralogie Monatshefte, 56–64.Google Scholar
Yang, Z. and Pertlik, F. (1993) Huanghoite-(Ce), BaCe(CO3)2F, from Khibina, Kola Peninsula, Russia: Redetermination of the crystal structure with a discussion on the space group symmetry. Neues Jahrbuch für Mineralogie Monatshefte, 163–171.Google Scholar
Supplementary material: File

Piilonen et al. supplementary material

Supplementary Data

Download Piilonen et al. supplementary material(File)
File 14.7 KB