 | Torró, L., Villanova, C., Castillo, M., Campeny, M., Gonçalves, A. O., Melgarejo, J. C. (2012) Niobium and rare earth minerals from the Virulundo carbonatite, Namibe, Angola. Mineralogical Magazine, 76 (2) 393-409 doi:10.1180/minmag.2012.076.2.08 | Journal (article/letter/editorial) | | * Departament de Cristal·lografia, Mineralogı́a i Dipòsits Minerals, Universitat de Barcelona, c/Martı́...Departamento de Geologia, Faculdade de Ciências, Universidade Agostinho Neto, Av. 4 de Fevereiro 7,...one of the largest in the world and contains pyrochlore as an accessory mineral in all of the carbonatite...breccias and trachytoids). The primary magmatic pyrochlore is fluorine dominant and typically contains about...replacement of the primary pyrochlore by a second generation of pyrochlore with less F and Na. Low-temperature |  | Andersen, Allen K., Clark, James G., Larson, Peter B., Donovan, John J. (2017) REE fractionation, mineral speciation, and supergene enrichment of the Bear Lodge carbonatites, Wyoming, USA. Ore Geology Reviews, 89. 780-807 doi:10.1016/j.oregeorev.2017.06.025 | Journal (article/letter/editorial) | | abundance of secondary REE phosphates (rhabdophane group, monazite, and fluorapatite), while HREE-enrichment...lateritically weathered carbonatite at Araxá and Catalão I, Brazil and Mt. Weld, Australia (cf., Zaitsev et al., 1998;...Juquiá, Brazil; Bayan Obo, China; Karonge, Burundi; and the Barra do Itapirapuã carbonatite, Brazil, among...biotite/phlogopite, aegirine-augite, fluorapatite, ilmenite, pyrochlore/betafite, pyrrhotite, pyrite, sphalerite, and...(Mariano, 1978b). Our investigations show U-rich pyrochlore/betafite occurs as inclusions in ilmenite or |  | | Journal (article/letter/editorial) | | August 4, 1987; accepted October 22, 1987 Summary Pyrochlore is present as a residual mineral within a Mesozoic-Cainozoic...Leaching of the A-site ions Na and Ca from the pyrochlore structure occurred during weathering and the...which were subsequently filled by Fe 3+. The pyrochlore mineral chemistry changes markedly with depth...weathering profile and the sequence: Na-Ca pyrochlore, strontian pyrochlore, strontiopyrochlore, ceriopyrochlore...top of the profile. This vertical zonation in pyrochlore mineral chemistry is the result of leaching and |  | | Book (edition) | | Salinas, Peru, H Variscite, xx 5 mm, Iturnbiara, Brazil, H Rhodocbrosite, polished, 50 mm, Capillitas,... China, H Page 1: MuscO\ite. 45 mm, Linopolis, Brazil, H Page 2: Vivianite, I 00 mm, Huanzala, Bolivia...Ethiopia, G Page 12: Brazilianite, 35 mm, Linopolis, Brazil, H Page 13: Gold, 35 mm.Eagle's est Mine, California...to the chemical formula, allegiance to a mineral group, symmetry and crystal structure as well as the strongest...chemical formula, structure (crystal system, space group, and unit cell dimensions), and at least some other |  | | Journal (article/letter/editorial) | | EYAL,1990a). The major monazite cations (Ce and La) do not form comparable aqueous complexes. Three additional...of the ekrnents The extreme variations of the act&de leach rates in the bi~arbonate~arbonate sotution...picture (Figs. 1 and 2), the R(228Th/232Th) data do not. Although initially R(228Th/232Th) values decrease...be linear, although the experimental uncertainties do not rule out curvature similar to that observed for...to the data. The release fraction data for ‘j2Th do not show the distinct curvature of the 23xUdata, |  | | Book (edition) | | International Symposium on Carbonatites in Pocos de Caldas, Brazil for which this writer was keynote speaker... Pakistan, Quebec, Finland, Guyana, Venezuela, Brazil, Paraguay, Angola and South-West Africa, i.a. Carbonatites...Quebec and Araxa, Brazil) and important sources of P, Ti, Cu and CaCO; (Jacupiranga, Brazil). In addition...petrologists as those of the undersaturated alkalic group—the nepheline syenites and their relatives. Rare...Carbonatites of the World United States Canada Brazil Greenland, Europe, and the U.S.S.R. Africa India |  | | Book (edition) | | extensively rewritten by the book’s distinguished group of authors in the light of new research and important...es: CW DB DE DG DJ DK DM DO DP DS EB EO EE FM GD GG GH GM Arnold Hampson David Baker Ben De Witt William...all varietal names, synonyms, spelling variants, group names, and so forth; only names in contemporary...contemporary use have been included. Most of the mineral group lists presented were taken from the Glossary of Mineral... All faces or other surfaces on a given mineral do not necessarily exhibit the same luster. Some minerals | | | Book (edition) | | extensively rewritten by the book's distinguished group of authors in the light of new research and important...Tsurneb, Namibia, (lower, right) gold, Amazonas, Brazil All specimens from the collection of Eugene and...figure caption code. Arnold Hampson David Baker Ben De Witt William Larson Carlos Barbosa Cal and Kerith...Mines cw Charles and Marcelle Weber DB Dan Behnke DE Demetrios Pohl DG Richard Graeme DJ D. K. Jones Douglas...Douglas K. Miller DK Arizona-Sonora Desert DM Museum DO = "Donald Olson Delma Perry DP DS David Shannon EB |  | | Journal (article/letter/editorial) | | . . . . . . . . . . . . . . . . . . . Platinum group elements (PGE) . . . . . . . . . . . . . . . . ...platinum-group-element deposits . . . . . . . . . . . . 6.3. Structure-related platinum-group-element...Sedimentary platinum-group-element deposits . . . . . . . . . . 6.5. Platinum-group-element supply and.... . . 45.1. Chemistry and mineralogy of garnet-group minerals . . . . . . . . 45.2. Magmatic garnet deposits... . . . . . . . . . . . . . . . . . . . Epidote-group minerals . . . . . . . . . . . . . . . . . . . | | | Journal (article/letter/editorial) | | . . . . . . . . . . . . . . . . . . . Platinum group elements (PGE) . . . . . . . . . . . . . . . . ...platinum-group-element deposits . . . . . . . . . . . . 6.3. Structure-related platinum-group-element...Sedimentary platinum-group-element deposits . . . . . . . . . . 6.5. Platinum-group-element supply and.... . . 45.1. Chemistry and mineralogy of garnet-group minerals . . . . . . . . 45.2. Magmatic garnet deposits... . . . . . . . . . . . . . . . . . . . Epidote-group minerals . . . . . . . . . . . . . . . . . . . |  | | Book (edition) | | attempt a complete description of a small mineral group to uncover the unsatisfactory state of our present...well render the volume difficult to use by a large group of potential readers not familiar with structural/chemical...with the inherent problems of end-member names vs. group names and related aspects of nomenclature. Rather...spelling variants, descriptive names, mixtures, group names, chemical names, etc., found in the literature...etc. All faces or other surfaces on a given mineral do not necessarily exhibit the sa1ne luster. Mode of |  | | Book | | extreme chemical coherence of the rare earth element group, which makes separation of the individual members...behaviour but sufficiently significant fractionations do occur, which have proved to be of great importance...lutetium (atomic numbers 57—71), are members of Group IIIA in the periodic table (Fig. 1.1) and all have...fractionation in a rock or mineral can be a pointer 1 Group H 3 1Li Na VIIIB 2 HA MB 5 Be 12 Mg IIIA...42 43 73 74 58 90 23 4 V Nb Ta Ce Th Group VIII 27 28 44 45 75 76 77 59 60 61 91 |  | | Book | | be uneconomic. On their return to Rovaniemi the group performed test panning at various sites, and a promising...extension of the iron ores could be found, and the group moved from Salmijärvi east to the fells of Petsamo...disturbances in a place called Otanmäki. When the explorer group, led by Veikko Pääkkönen, heard of this, they moved...and V-rich magnetite gabbros enriched in platinum-group elements (PGE). The magnetite gabbro also contained...investigations carried out in the area yielded pyrochlore, a Nb-mineral characteristically present in carbonatites |
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