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Fluorlamprophyllite, Na3(SrNa)Ti3(Si2O7)2O2F2, a new mineral from Poços de Caldas alkaline massif, Morro do Serrote, Minas Gerais, Brazil

Published online by Cambridge University Press:  28 February 2018

Marcelo B. Andrade ,
Hexiong Yang ,
Robert T. Downs ,
Gunnar Färber ,
Reynaldo R. Contreira Filho ,
Stanley H. Evans ,
Clayton W. Loehn  and
Benjamin N. Schumer
Marcelo B. Andrade*
Affiliation:
Department of Geosciences, University of Arizona, 1040 East 4th Street, Tucson, Arizona, 85721-0077, USA Department of Physics and Interdisciplinary Science, São Carlos Institute of Physics, University of São Paulo, PO Box 369, 13560-970, São Carlos, SP, Brazil
Hexiong Yang
Affiliation:
Department of Geosciences, University of Arizona, 1040 East 4th Street, Tucson, Arizona, 85721-0077, USA
Robert T. Downs
Affiliation:
Department of Geosciences, University of Arizona, 1040 East 4th Street, Tucson, Arizona, 85721-0077, USA
Gunnar Färber
Affiliation:
Bornsche Strasse 9, 39326, Samswegen, Germany
Reynaldo R. Contreira Filho
Affiliation:
Rua Murici 62, 13.098-315, Campinas, SP, Brazil
Stanley H. Evans
Affiliation:
Department of Geosciences, University of Arizona, 1040 East 4th Street, Tucson, Arizona, 85721-0077, USA
Clayton W. Loehn
Affiliation:
Shared Instrumentation Facility, Louisiana State University, Baton Rouge, LA, USA
Benjamin N. Schumer
Affiliation:
Department of Geosciences, University of Arizona, 1040 East 4th Street, Tucson, Arizona, 85721-0077, USA
*
*E-mail: [email protected]
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Abstract

A new mineral species, fluorlamprophyllite (IMA2013-102), ideally Na3(SrNa)Ti3(Si2O7)2O2F2, has been found in the Poços de Caldas alkaline massif, Morro do Serrote, Minas Gerais, Brazil. Alternatively, the idealized chemical formula could be written as (SrNa)[(Na3Ti)F2][Ti2(Si2O7)2O2], setting the large interlayer cations before the cations of the layer. Fluorlamprophyllite is the F-analogue of lamprophyllite. It is associated with aegirine, analcime, natrolite, nepheline and microcline. Fluorlamprophyllite crystals are brownish-orange and bladed. The mineral is transparent with a pale yellow streak and an adamantine lustre. It is brittle and has a Mohs hardness of ~3; cleavage is perfect on {100} and no parting was observed. The calculated density is 3.484 g/cm3. Optically, fluorlamprophyllite is biaxial (+), with α = 1.735(7), β = 1.749(7) and γ = 1.775(9) and 2Vmeas = 72(3)°. An electron microprobe analysis produced an average composition (wt.%) (9 points) of Na2O 10.63(30), K2O 0.47(3), SiO2 30.51(13), SrO 18.30(24), MgO 0.81(17), Al2O3 0.23(2), CaO 1.11(7), MnO 5.03(38), TiO2 27.41(87), Fe2O3 2.45(37), F 2.86(23), plus H2O 1.00 (added to bring the total close to 100%), –O = F –1.20, with the total = 98.61%. The elements Nb and Ba were sought, but contents were below microprobe detection limits. The resultant chemical formula was calculated on the basis of 18 (O + F) atoms per formula unit. The addition of 1.00 wt.% H2O brought [F+(OH)] = 2 pfu, yielding (Na2.63Sr1.35Mn0.54Ca0.15Mg0.15K0.08)Σ4.90(Ti2.63Fe0.24Al0.04)Σ2.91Si3.89O16[F1.15(OH)0.85]Σ2.00. The mineral is monoclinic, with space group C2/m and unit-cell parameters a = 19.255(2), b = 7.0715(7), c = 5.3807(6) Å, β = 96.794(2)° and V = 727.5(1) Å3. The structure is a layered silicate inasmuch as the O atoms are arranged in well-defined, though not necessarily close-packed layers.

Keywords

fluorlamprophylliteNa3(SrNa)Ti3(Si2O7)2O2F2crystal structureX-ray diffractionlamprophyllite group
Type
Article
Information
Mineralogical Magazine , Volume 82 , Issue 1 , February 2018 , pp. 121 - 131
Copyright
Copyright © Mineralogical Society of Great Britain and Ireland 2018 

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Footnotes

Associate Editor: Ian Graham

References

Aksenov, S.M., Rastsvetaeva, R.K. and Chukanov, N.V. (2014) The crystal structure of emmerichite Ва2Na3Fe3+Ti 2(Si2O7)2O2F2, a new lamprophyllite-group mineral. Zeitschrift für Kristallographie – Crystalline Materials, 229, 1–7.Google Scholar
Brese, N.E. and O'Keeffe, M. (1991) Bond-valence parameters for solids. Acta Crystallographica, B47, 192–197.CrossRefGoogle Scholar
Chukanov, N.V., Moiseev, M.M., Pekov, I.V., Lazebnik, K.A., Rastsvetaeva, R.K., Zayakina, N.V., Ferraris, G. and Ivaldi, G. (2004) Nabalamprophyllite Ba(Na,Ba){Na3Ti[Ti2O2Si4O14](OH,F)2} – a new layer titanosilicate of the lamprophyllite group from Inagli and Kovdor alkaline-ultramafic massifs, Russia. Zapiski Vserossijskogo Mineralogicheskogo Obshchestva, 133, 59–72.Google Scholar
Chukanov, N.V., Rastsvetaeva, R.K., Britvin, S.N., Virus, A.A., Belakovskiy, D.I., Pekov, I.V., Aksenov, S.M. and Ternes, B. (2011) Schüllerite, Ва2Na(Mn,Ca)(Fe3+,Mg,Fe2+)2Ti2(Si2O7)2(O,F)4, a new mineral species from the Eifel volcanic district, Germany. Geology of Ore Deposits, 53(8), 767–774.Google Scholar
Chukanov, N.V., Pekov, I.V., Rastsvetaeva, R.K., Aksenov, S.M., Zadov, A.E., Van, K.V., Blass, G., Schüller, W. and Ternes, B. (2012) Lileyite, Ba2(Na,Fe,Ca)3MgTi2(Si2O7)2O2F2, a new lamprophyllite-group mineral from the Eifel volcanic area, Germany. European Journal of Mineralogy, 24, 181–188.CrossRefGoogle Scholar
Chukanov, N.V., Rastsvetaeva, R.K., Aksenov, S.M., Blass, G., Pekov, I.V., Belakovskiy, D.I., Tschörtner, J., Schüller, W., Ternes, B. (2014) Emmerichite, Ba2Na(Na,Fe2+)2(Fe3+,Mg)Ti2(Si2O7)2O2F2, a new lamprophyllite-group mineral from the Eifel paleovolcanic region, Germany. New Data on Minerals, 49, 5–13.Google Scholar
Downs, R.T., Bartelmehs, K.L., Gibbs, G.V. and Boisen, M.B. Jr. (1993) Interactive software for calculating and displaying X-ray or neutron powder diffractometer patterns of crystalline materials. American Mineralogist, 78, 1104–1107.Google Scholar
Ferraris, G. and Gula, A. (2005) Polysomatic aspects of microporous minerals – heterophyllosilicates, palysepioles and rhodesite-related structures. Pp. 69–104 in: Micro- and Mesoporous Mineral Phases. Reviews in Mineralogy & Geochemistry, 57. Mineralogical Society of America and the Geochemical Society, Chantilly, Virginia, USA.CrossRefGoogle Scholar
Kampf, A.R., Roberts, A.C., Venance, K.E., Dunning, G.E. and Walstrom, R.E. (2011) Ferroericssonite, the Fe2+ analogue of ericssonite, from eastern Fresno County, California, USA. Canadian Mineralogist, 49, 587–594.Google Scholar
Krivovichev, S.V., Armbruster, T., Yakovenchuk, V.N., Pakhomovsky, Y.A. and Men'shikov, Y.P. (2003) Crystal structures of lamprophyllite-2M and lamprophyllite-2O from the Lovozero alkaline massif, Kola peninsula, Russia. European Journal of Mineralogy, 15, 711–718.CrossRefGoogle Scholar
Leonardi, F.A., Ladeira, F.S.B. and dos Santos, M. (2011) Paleosurfaces and bauxite profiles in the Poços de Caldas Plateau, São Paulo/Minas Gerais, Brazil. Geociências, 30, 147–160.Google Scholar
Matsubara, S. (1980) The crystal structure of orthoericssonite. Mineralogical Journal, 10, 107–121.Google Scholar
Moore, P.B. (1971) Ericssonite and orthoericssonite, two new members of the lamprophyllite group, from Långban, Sweden. Lithos, 4, 137–145.CrossRefGoogle Scholar
Rastsvetaeva, R.K., Aksenov, S.M. and Chukanov, N.V. (2011) Crystal structure of schüllerite, a new mineral of the heterophyllosilicate family. Doklady Chemistry, 437, 499–503.CrossRefGoogle Scholar
Rastsvetaeva, R.K., Chukanov, N.V. and Aksenov, S.M. (2016) The crystal chemistry of lamprophyllite-related minerals: a review. European Journal of Mineralogy, 28, 915–930.Google Scholar
Saf'yanov, Y.N., Vasil'eva, N.O., Golovachev, V., Kuz'min, E.A. and Belov, N. (1983) Crystal structure of lamprophyllite. Soviet Physics Doklady, 28, 207–209.Google Scholar
Sheldrick, G.M. (2007) SADABS. University of Göttingen, Germany.Google Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112–122.Google Scholar
Sokolova, E. (2006) From structure topology to chemical composition. I. Structural hierarchy and stereochemistry in titanium disilicate minerals. Canadian Mineralogist, 44, 1273–1330.Google Scholar
Sokolova, E. and Cámara, F. (2008) From structure topology to chemical composition. III. Titanium silicates: the crystal chemistry of barytolamprophyllite. Canadian Mineralogist, 46, 403–412.CrossRefGoogle Scholar
Sokolova, E. and Hawthorne, F.C. (2008) From structure topology to chemical composition. IV. Titanium silicates: the orthorhombic polytype of nabalamprophyllite from Lovozero massif, Kola Peninsula, Russia. Canadian Mineralogist, 46, 1323–1331.Google Scholar
Ulbrich, H.H.G.J. (1984) A petrografia, a estrutura e o quimismo de nefelina sienitos do maciço alcalino de Poços de Caldas. PhD Thesis, Universidade de São Paulo, Instituto de Geociências, Brazil.Google Scholar
Woodrow, P.J. (1964) Crystal structure of lamprophyllite. Nature, 204, 375.Google Scholar
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