[en] Graulichite-(Ce), ideally CeFe33+(AsO4)(2)(OH)(6), is a new mineral species from Hourt, Stavelot Massif, Belgium. It occurs in the most altered parts of a Devillian quartzite (Lower to Middle Cambrian), in close association with arsenopyrite, scorodite, mimetite, pharmacosiderite, and goethite. Graulichite-(Ce) forms 80 to 150 mum spherical aggregates of rhombohedral crystals, 50 to 80 mum length, which show the forms {10 (1) over bar2} and {10 (11) over bar}. The mineral is transparent and exhibits a light-green to brownish colour, with a resinous lustre. It is non-fluorescent and shows an irregular fracture, without any perceptible cleavage. The calculated density is 4.42 g/cm(3). Graulichite-(Ce) is uniaxial negative, with a mean refractive index close to 1.97(1) (lambda=590 nm), pleochroic from light green to yellowish. Electron microprobe analyses gave As2O5 31.20, P2O5 0.03, SO3 0.06, SiO2 0.03, Al2O3 3.09, Fe2O3 30.65, SrO 0.24, PbO 0.07, BaO 3.95, CaO 0.03, La2O3 2.26, Ce2O3 15.73, Nd2O3 2.08, H2O (calc.) 8.37, total 97.79 wt. %. The resulting empirical formula, calculated on the basis of 6 cations, is (Ce0.67Ba0.18La0.10Nd0.09Sr0.02)(Sigma1.06) (Fe2.683+Al0.42)(Sigma3.10)[(As(1.89)S(.001)square(0.10))(Sigma2.00)O-8][(OH)(5.57)(H2O)(0.43)](Sigma6.00). The single-crystal unit-cell parameters are a=7.288(2) and c=16.812(9) Angstrom, space group R (3) over barm. The seven strongest lines in the X-ray powder-diffraction pattern [d(in Angstrom)(I)(hkil)] are: 3.052(100)(11 (2) over bar3), 3.636(40)(11 (2) over bar0), 2.239(35)(10 (1) over bar7), 1.817(35)(22 (4) over bar0), 2.792(30)(0006), 5.906(25)(10 (1) over bar1), 1.968(25)(30 (3) over bar3). Graulichite-(Ce) is the iron analogue of arsenoflorencite-(Ce), and belongs to the crandallite mineral group, with the alunite-type structure. The crystal structure of graulichite-(Ce) has been refined, based on single-crystal X-ray diffraction data, to R=0.048.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Hatert, Frédéric ; Université de Liège - ULiège > Département de géologie > Minéralogie et cristallochimie
Pasero, Marco
Fransolet, André-Mathieu ; Université de Liège - ULiège > Département de géologie > Minéralogie et cristallochimie
Lefèvre, Pierre
Language :
English
Title :
Graulichite-(Ce), a new arsenate mineral from the Stavelot Massif, Belgium
Alexandre, J. & Thorez, J. (1995): Au Secondaire et au Tertiaire, l'Ardenne tropicale. in A. Demoulin ed.: "L'Ardenne, essai de géographie physique". Groupe Graphique Chauveheid, Liège, 238 p.
Barthoux, J. (1925): Description d'un minéral nouveau: In dussertite. C. R. Acad. Sci, Paris, 180, 299-301.
Birch, WD., Pring, A., Gatehouse, B.M. (1992): Segnitite, PbFe3H(AsO4)2(OH)6, a new mineral in the lusungite group from Broken Hill, New South Wales, Australia. Am. Mineral., 77, 656-659.
Bless, M., Bouckaert, J., Camelbeek, T, Dejonghe, L., Demoulin, A., Dupuis, C., Felder, P., Geukens, F., Gullentops, E, Hance, L., Jagt, J., Juvigné, E., Kramm, U., Ozer, A., Pissart, A., Robaszynski, F., Schumacker, R., Smolderen, A., Spaeth, G., Steemans, P., Streel, M., Vandenven, G., Vanguestaine, M., Walter, R., Wolf, M. (1990): The Stavelot massif from Cambrian to recent. A survey of the present state of knowledge. Annales de la Société géologique de Belgique, 113, 53-73.
Blessing, R.H. (1995): An empirical correction for absorption anisotropy. Acta Cryst., A51, 33-38.
Blount, A.M. (1974): The crystal structure of crandallite. Am. Mineral., 59, 41-47.
Burnham, C.W. (1991): LCLSQ version 8.4, last-squares refinement of crystallographic lattice parameters. Dept. of Earth & Planetary Sciences, Harvard University, 24 p.
Farrugia, L.J. (1999): WinGX suite for small-molecule single-crystal crystallography. J. Appl. Cryst., 32, 837-838.
Ferket, H., Muchez, P., Schroyen, K., Sintubin, M. (1998): Metamorphism in the Stavelot-Venn Massif: a study of quartz veins in the basal devonian conglomerates (Lochkovian). Aardkundige Mededelingen, 9, 7-16.
Hanson, A. (1983): Etude minéralogique de filons de la bordure méridionale du Massif de Stavelot. Unpublished Diploma Thesis, University of Liège, 84 p.
Hanson, A., Dehove, J., Debbaut, V, Brunel, J. (1999): La découverte d'or natif dans le quartzite devillien de Hourt autorise un autre regard sur le site de "Rompt-le-Cou". Glain et Salm, Haute Ardenne, 51, 4-10.
Hatert, F. (1996): Etude minéralogique préliminaire de quelques sulfures du massif de Stavelot. Unpublished Diploma Thesis, University of Liège, 48 p.
Hatert, F. (1997): L'arsénopyrite du Massif de Stavelot, Belgique. Bull. Société royale des Sciences de Liège, 66(6), 381-390.
Hatert, F, Blondieau, M., Dehove, J., Fransolet, A.M. (1998) : Les minéraux secondaires en relation avec les sulfures de la région de Vielsalm, Belgique. Bull. Société royale des Sciences de Liège, 67(6), 281-289.
Hatert, F., Deliens, M., Fransolet, A.-M., Van Der Meersche, E. (2002): Les minéraux de Belgique. Deuxième édition. Editions de l'Institut royal des Sciences naturelles de Belgique, 304 p.
Jambor, J.L. (1999): Nomenclature of the alunite supergroup. Can. Mineral., 37, 1323-1341.
Kato, T. (1987): Further refinement of the goyazite structure. Mineral. J., 13, 390-396.
Kato, T. (1990): The crystal structure of florencite. N. Jb. Mineral. Mh., 1990, 227-231.
Kharisun, Taylor, M.R., Bevan, D.J.M., Pring, A. (1997): The crystal structure of kintoreite, PbFe3(PO4)2(OH,H2O)6. Min. Mag., 61, 123-129.
Kolitsch, U. & Pring, A. (2001): Crystal chemistry of the crandallite, beudantite and alunite groups: a review and evaluation of the suitability as storage materials for toxic metals. J. Mineral. Petrol. Sci., 96, 67-78.
Kolitsch, U., Slade, P.G., Tiekink, E.R.T., Pring, A. (1999): The structure of antimonian dussertite and the role of antimony in oxysalt minerals. Min. Mag., 63, 17-26.
Kramm, U. (1980): Muskovit-Paragonit Phasenbeziehungen in niedriggradig metamorphen Schiefern des Venn-Stavelot Massivs, Ardennen. Tschermaks Mineralogische und Petrographische Mitteilungen, 27, 153-167.
Kramm, U. (1982): Die Metamorphose des Venn-Stavelot-Massivs, nordwestliches Rheinisches Schiefergebirge: Grad, Alter und Ursache. Decheniana, 135, 121-178.
Kramm, U., Spaeth, G., Wolf, M. (1985): Variscan metamorphism in the NE Stavelot-Venn Massif, Ardennes: a new approach to the question of regional dynamothermal or contact metamorphism. N. Jb. Geol. Paläont. Abh., 171, 311-327.
Lefèvre, P. (2001): La présence d'arsenic dans les filons à sulfures du Devillien de Hourt, Massif de Stavelot. Unpublished Diploma Thesis, University of Liège, 45 p.
Lefèvre, P. & Hatert, F. (in press): Or natif, arsénopyrite et minéraux secondaires dans les quartzites devilliens de Hourt, Massif de Stavelot, Belgique. Geologica Belgica.
Mandarino, J.A. (1981): The Gladstone-Dale relationship: Part IV. The compatibility concept and its application. Can. Mineral., 19, 441-450.
Nickel, E.H. & Temperly, J.E. (1987): Arsenoflorencite-(Ce): a new arsenate mineral from Australia. Min. Mag., 51, 605-609.
Radoslovich, E.W. (1982): Refinement of gorceixite in Cm. N. Jb. Mineral. Mh, 1982, 446-464.
Schreyer, W. (1975): New petrologic evidence for Hencynian metamorphism in the Venn-Stavelot Massif, Belgium. Geologische Rundschau, 64, 819-830.
Schreyer, W., Fransolet, A.-M., Bernhardt, H.-J. (2001): Hollandite-strontiomelane solid solutions coexisting with kanonaite and braunite in late quartz veins of the Stavelot Massif, Ardennes, Belgium. Contrib. Mineral. Petrol., 141, 560-571.
Schroyen, K. & Muchez, Ph. (2000): Evolution of metamorphic fluids at the Variscan fold-and-thrust belt in Eastern Belgium Sedimentary Geology, 131, 163-180.
Sheldrick, G.M. (1993): SHELXL93. Program for the Refinement of Crystal Structures. University of Göttingen, Germany.
Theunissen, K. & Martin, H. (1969): Découverte d'un phosphate alumineux de terres rares dans un coticule de Vielsalm. Annales de la Société géologique de Belgique, 92, 173-176.
Verniers, J., Herbosch, A., Vanguestaine, M., Geukens, F., Delcambre, B., Pingot, J.L., Belanger, I., Hennebert, M., Debacker, T., Sintubin, M., De Vos, W. (2001): Cambrian-Ordovician-Silurian lithostratigraphic units (Belgium). Geologica Belgica, 4, 5-38.
Walenta, K. (1966): Beiträge zur Kenntnis seltener Arsenatmineralien unter besonderer Berücksichtigung von Vorkommen des Schwarzwaldes. Tschermaks Mineralogische und Petrographische Mitteilungen, 11, 121-164.
Walenta, K. (1981): Mineralien der Beudantit-Crandallitgruppe aus dem Schwarzwald : Arsenocrandallit und sulfatfreier Weilerit. Schweiz. Mineral Petrogr Mitt., 61, 23-35.
Walenta, K. & Dunn, P.J. (1984): Arsenogoyazit, ein neues Mineral der Crandallitgruppe aus dem Schwarzwald. Schweiz. Mineral. Petrogr. Mitt., 64, 11-19.
Walenta, K., Zwiener, M., Dunn, P.J. (1982): Philipsbornit, ein neues Mineral der Crandallitreihe von Dundas auf Tasmanien. N. Jb. Mineral. Mh, 1982, 1-5.