http://www.cnr.it/ontology/cnr/individuo/prodotto/ID29186

Oxykinoshitalite, a new mica from Fernando-De-Norohna island, Brazil: occurence and crystal structure. (Articolo in rivista)

Type

Prodotto della ricerca (Classe)
Articolo in rivista (Classe)

Label

Oxykinoshitalite, a new mica from Fernando-De-Norohna island, Brazil: occurence and crystal structure. (Articolo in rivista) (literal)

Anno

2005-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

10.2113/gscanmin.43.5.1501 (literal)

Alternative label

Kogarko L.N.; Uvarova Y.A.; Sokolova E.; Hawthorne F.C.; Ottolini L.; Grice J.D. (2005)
Oxykinoshitalite, a new mica from Fernando-De-Norohna island, Brazil: occurence and crystal structure.
in Canadian mineralogist; Mineralogical Association of Canada, Ottawa (Canada)
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

Kogarko L.N.; Uvarova Y.A.; Sokolova E.; Hawthorne F.C.; Ottolini L.; Grice J.D. (literal)

Pagina inizio

1501 (literal)

Pagina fine

1510 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

43 (literal)

Rivista

Canadian mineralogist (Rivista)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#note

n.5 (literal)

Note

ISI Web of Science (WOS) (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

Kogarko L.N. 1); Uvarova Y.A. 2); Sokolova E. 2); Hawthorne F.C. 2); Ottolini L. 3); Grice J.D. 4); 1) Russian Acad Sci, Vernadsky Inst Geochem, Moscow 119991, Russia; 2) Univ Manitoba, Dept Geol Sci, Winnipeg, MB R3T 2N2, Canada; 3) IGG, Sez Pavia, I-27100 Pavia, Italy; 4) Canadian Museum Nat, Div Res, Ottawa, ON K1P 6P4, Canada; (literal)

Titolo

Oxykinoshitalite, a new mica from Fernando-De-Norohna island, Brazil: occurence and crystal structure. (literal)

Abstract

Oxykinoshitalite, ideally Ba (Mg-2 Ti4+) (Si-2 Al-2) O-10 O-2, is a new species of mica from Fernando de Noronha Island, Pernambuco, Brazil; it is found in an olivine nephelinite with olivine, clinopyroxene, Fe-Ti oxide, nepheline, calcite, apatite and K-rich feldspar. Oxykinoshitalite forms corroded irregularly shaped grains 0.03 to 0.05 mm across, and its color varies from bright orange to brown. It is brittle, H = 21/2, D-obs = 3.3(1), D-calc, = 3.45 g/cm(3), has a brown streak, vitreous luster and does not fluoresce in ultraviolet light; it has a perfect cleavage on {001} and a splintery fracture. In transmitted plane-polarized light, oxykinoshitalite is strongly pleochroic, X pale brown, Y approximate to Z deep red-brown; X boolean AND c = 2 degrees (in beta obtuse), Y = b, Z boolean AND a = 8 degrees (in beta obtuse), with absorption X < Y approximate to Z. It is biaxial positive, alpha 1.708 +/- 0.001, beta 1.710 +/- 0.001, gamma 1.719 +/- 0.001, 2V(obs) = 56 +/- 2 degrees, 2V(calc) = 51 degrees. Oxykinoshitalite is monoclinic, space group C2/m, a 5.3516(7), b 9.2817(11), c 10.0475(13) angstrom, beta 100.337(3)degrees, V 490.98(18) angstrom(3), Z = 2. The strongest ten X-ray-diffraction lines in the powder pattern [d in angstrom(I)(hkl)] are: 2.637(10)((1) over bar 31), 2.172(9)((1) over bar 33), 3.646(7)((1) over bar 12), 3.130(7)(112), 3.383(6)(002), 2.902(5)((1) over bar 13), 2.435(5)(201), 1.988(5)(133), 1.661(5)((1) over bar 35), 1.547(5)(312), and 1.526(5)(M). Analysis by a combination of electron microprobe, SIMS and crystal-structure refinement gives SiO2 28.92, Al2O3 15.26, TiO2 11.94, Cr2O3 0.03, Fe2O3 9.07, FeO 3.84, MnO 0.14, MgO 10.74, CaO 0.03, BaO 15.49, Na2O 0.39, K2O 4.05, F 0.91, H2O 0.55, sum 100.97 wt.%; V, Ni, Zn, Sr, Cl were not detected. The formula unit, calculated on the basis of 12(O,OH,F) is (Ba-0.50 K-0.43 Na-0.07)(Sigma 1.00) (Mg-1.33 Fe-0.27(2+) Mn-0.01(2+) Fe-0.57(3+) Ti-0.74(4+))(Sigma 2 92) (Si2.40Al1.49)(Sigma 3) (89) O-10 [O-1.46 (OH)(0.30) F-0.24](Sigma 2.00). Refinement of the crystal structure shows it to be the 1M polytype. The refinement converged to R-1 = 4.3% for 585 unique (F-0 > 4 sigma F-0) reflections, collected on a Broker single-crystal P4 diffractometer with a CCD detector and MoK alpha X-radiation. Electron-microprobe and SIMS analysis of the crystal used to collect the data on X-ray intensities gave the empirical formula (Ba-0.47 K-0.42 Na-0.06 Ca-0.01)(Sigma 0 96) (Mg-1.35 Fe2+ (0.28) Fe-0.59(2+) Ti-0.75(4+) Mn-0.01)(Sigma 2.99) [Si-2.31 Al-1.56](Sigma 3.97) O-10 (O-1.44 OH0.31 F-0.25)(Sigma 2 00). The oxygenian Ti-dominant analogue of kinoshitalite occurs in olivine nephelinite and is associated with olivine, clinopyroxene, Fe-Ti oxide, nepheline, calcite, apatite and K-rich feldspar. There is one tetrahedrally coordinated T site, < T-O > = 1.671 angstrom, occupied by (Si-2.31 Al-1.56). There are two octahedrally coordinated sites, M(1) occupied by (Mg-0.52 Fe-0.13(2+) Fe-0.27(2+) Ti-0.08(4+)) with < M(1)-O > = 2.110 angstrom, and M(2) occupied by (Mg-0.84 Fe-0.15(2+) Fe-0.33(3+) Mn-0.01 Ti-0.67(4+)) with < M(2)-O > = 2.065 angstrom. The interstitial [12]-coordinated I site is occupied by (Ba-0.47 K-0.42 Na-0.06 Ca-0.01), with < I-O > = 3.107 angstrom. There are two main coupled substitutions in this structure: (1) Ti4+ for Mg, primarily at the M(2) site, and O2- for (OH)(-) and F- at the O(4) site, and (2) K for Ba at the I site, and Si for Al at the T site. (literal)

Editore