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  • 1.
    Ardit, Matteo
    et al.
    University of Ferrara, Italy.
    Cámara, Fernando
    University of Milano, Italy.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Vanadium-induced coloration in grossite (CaAl4O7) and hibonite (CaAl12O19)2021Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 106, nr 4, s. 599-608Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High concentrations of vanadium cause very unusual coloration in hibonite (purple) and grossite (light violet) crystals in an exotic mineral assemblage from Sierra de Comechingones (Argentina). In the hibonite (CaAl12O19) structure vanadium ions, in various valence states (divalent, trivalent, and tetravalent), may be distributed over five crystallographic sites with coordinations corresponding to different polyhedra, namely, three unequal octahedra [M1 (D3d), M4 (C3ν), and M5 (Cs)], one M3 tetrahedron (C3ν), and one unusual fivefold-coordinated trigonal bipyramid M2 (D3h). Possible locations of vanadium ions in grossite (CaAl4O7) are limited to two crystallographically distinct sites (T1 and T2, both C1) in tetrahedral coordination.

    The combination of single-crystal X-ray diffraction and absorption spectroscopy techniques aided by chemical analyses has yielded details on the nature of the vanadium-induced color in both hibonite and grossite crystals. In hibonite, both M4 face-sharing octahedral and M2 trigonal bipyramid sites of the R-block are partially occupied by V3+. Strongly polarized bands recorded at relatively low energies in optical absorption spectra indicate that V2+ is located at the M4 octahedral site of the hibonite R-block. Chemical analyses coupled with an accurate determination of the electron densities at structural sites in hibonite suggest that the vanadium ions occupy about 10 and 5% of the M4 and M2 sites, respectively. For grossite, polarized optical absorption spectra reveal no indications of V2+; all observed absorption bands can be assigned to V3+ in tetrahedral coordination. Although not evident by the observed electron densities at the T sites of grossite (due to the low-V content), longer bond distances, and a higher degree of polyhedral distortion suggest that V3+ is located at the T2 site.

  • 2.
    Baker, Don R.
    et al.
    Department of Earth and Planetary Sciences, McGill University, Montreal, Quebec H3A 0E8, Canada;‡ Special collection papers can be found online at http://www.minsocam.org/MSA/AmMin/special-collections.html..
    Callegaro, Sara
    Centre for Earth Evolution and Dynamics (CEED), University of Oslo, PO Box 1028, Blindern N-0316 Oslo, Norway.
    De Min, Angelo
    Department of Mathematics and Geoscience, University of Trieste, via Weiss 2, 34128 Trieste, Italy.
    Whitehouse, Martin J.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Marzoli, Andrea
    Department of Land, Environment, Agriculture and Forestry, University of Padova, 16-35020 Legnaro, Padova, Italy.
    Fluorine partitioning between quadrilateral clinopyroxenes and melt2022Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 107, nr 2, s. 167-177Artikel i tidskrift (Refereegranskat)
  • 3.
    Biagion, Cristian
    et al.
    Università di Pisa, Italy.
    Bosi, Ferdinando
    Sapienza Università di Roma, Italy.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Pasero, Marco
    Università di Pisa, Italy.
    The crystal structure of turneaureite, Ca5(AsO4)3Cl, the arsenate analog of chlorapatite and its relationships with the arsenate apatites johnbaumite and svabite2017Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 102, s. 1981-1986Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The crystal structure of turneaureite, ideally Ca5(AsO4)3Cl, was studied using a specimen from the Brattfors mine, Nordmark, Värmland, Sweden, by means of single-crystal X-ray diffraction data. The structure was refinedto R1 = 0.017 on the basis of 716 unique reflectios with Fo > 4σ(Fo) in the P63/m space group, with unit-cell parameters a = 9.9218(3), c = 6.8638(2) Å, V = 585.16(4) Å3. The chemical composition of the sample, determined by electron-microprobe analysis, is (in wt%; average of 10 spot analyses): SO3 0.22, P2O5 0.20, V2O5 0.01, As2O5 51.76, SiO2 0.06, CaO 41.39, MnO 1.89, SrO 0.12, BaO 0.52, PbO 0.10, Na2O 0.02, F 0.32, Cl 2.56, H2Ocalc 0.58, O(≡F+Cl) –0.71, total 99.04. On the basis of 13 anions per formula unit, the empirical formula corresponds to (Ca4.82Mn0.17Ba0.02Sr0.01)∑5.02 (As2.94P0.02S0.02Si0.01)∑2.99O12[Cl0.47(OH)0.42F0.11]∑1.00.Turneaureite is topologically similar to the other members of the apatite supergroup: columns of face-sharing M1 polyhedra running along c are connected through TO4 tetrahedra with channels hosting M2 cations and X anions. Owing to its particular chemical composition, the studied turneaureite can be considered as a ternary calcium arsenate apatite; consequently it has several partially filledanion sites within the anion columns. Polarized single-crystal FTIR spectra of the studied sample indicate stronger hydrogen bonding and less diverse short-range atom arrangements around (OH) groups in turneaureite as compared to the related minerals johnbaumite and svabite. An accurate knowledge of the atomic arrangement of this apatite-remediation mineral represents an improvement in our understanding of minerals able to sequester and stabilize heavy metals such as arsenic in polluted areas.

  • 4.
    Biagioni, Cristian
    University of Pisa.
    Pasero, Marco
    University of Pisa.
    Bonaccorsi, Elena
    Lepore, Giovanni Orazio
    Zaccarini, Federica
    University of Leoben.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Crystal-chemistry of sulfates from the Apuan Alps (Tuscany, Italy). VI. Tl-bearingalum-(K) and voltaite from the Fornovolasco mining complex2020Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 105, s. 1088-1098Artikel i tidskrift (Refereegranskat)
  • 5.
    Biagioni, Cristian
    et al.
    Università di Pisa, Italy.
    Bosi, Ferdinando
    Sapienza Università di Roma, Italy.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Pasero, Marco
    Università di Pisa, Italy.
    The crystal structure of svabite, Ca5(AsO4)3F, an arsenate member of the apatite supergroup2016Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 101, s. 1750-1755Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The crystal structure of svabite, ideally Ca5(AsO4)3F, was studied using a specimen from the Jakobsberg mine, Värmland, Sweden, by means of single-crystal X‑ray diffraction data. The structure was refined to R1 = 0.032 on the basis of 928 unique reflections with Fo > 4s(Fo) in the P63/m space group, with unit-cell parameters a = 9.7268(5), c = 6.9820(4) Å, V = 572.07(5) Å3. The chemical composition of the sample, determined by electron-microprobe analysis, is (in wt%, average of 10 spot analyses): SO3 0.49, P2O5 0.21, V2O5 0.04, As2O5 51.21, SiO2 0.19, CaO 39.31, MnO 0.48, SrO 0.03, PbO 5.19, Na2O 0.13, F 2.12, Cl 0.08, H2Ocalc 0.33, O (≡ F+Cl) –0.91, total 98.90. On the basis of 13 anions per formula unit, the empirical formula corresponds to (Ca4.66Pb0.16Mn0.04Na0.03)Σ4.89(As2.96S0.04Si0.02P0.02)Σ3.04O12[F0.74(OH)0.24Cl0.01]. Svabite is topologically similar to the other members of the apatite supergroup: columns of face-sharing M1 polyhedra running along c are connected through TO4 tetrahedra with channels hosting M2 cations and X anions. The crystal structure of synthetic Ca5(AsO4)3F was previously reported as triclinic. On the contrary, the present refinement of the crystal structure of svabite shows no deviations from the hexagonal symmetry. An accurate knowledge of the atomic arrangement of this apatite-remediation mineral represents an improvement in our understanding of minerals able to sequester and stabilize heavy metals such as arsenic in polluted areas.

  • 6.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Zn-O tetrahedral bond length variations in normal spinel oxides2011Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 96, s. 594-598Artikel i tidskrift (Refereegranskat)
  • 7.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Henrik, Skogby
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Oxy-dravite, Na(Al2Mg)(Al5Mg)(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup2013Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 98, s. 1442-1448Artikel i tidskrift (Refereegranskat)
    Ladda ner fulltext (pdf)
    BosiPreprintAugSept_13
  • 8.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Lucchesi, Sergio
    Sapienza Università di Roma.
    Structural refinement of Mn-doped spinel: a case for tetrahedrally coordinated Mn3+ in an oxygen-based structure2007Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 92, s. 27-33Artikel i tidskrift (Refereegranskat)
  • 9.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    D'Ippolito, Veronica
    Sapienza Università di Roma.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Blue spinel crystals in the MgAl2O4-CoAl2O4 series: II. Cation ordering over short range and long range scales2012Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 97, s. 1834-1840Artikel i tidskrift (Refereegranskat)
  • 10.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Crystal chemistry of the magnetite-ulvöspinel series2009Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 94, s. 181-189Artikel i tidskrift (Refereegranskat)
  • 11.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Crystal chemistry of the MgAl2O4-MgMn2O4-MnMn2O4 system: Analysis of structural distortion in spinel and hausmannite-type structures2010Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 95, s. 602-607Artikel i tidskrift (Refereegranskat)
  • 12.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Crystal chemistry of the ulvöspinel-qandilite series2014Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, s. 847-851Artikel i tidskrift (Refereegranskat)
  • 13.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Stoichiometry of synthetic ulvöspinel single crystals2008Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 93, s. 1312-1316Artikel i tidskrift (Refereegranskat)
  • 14.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Reznitskii, Leonid
    Russian Academy of Science.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Vanadio-oxy-chromium-dravite, NaV3(Cr4Mg2)(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup 2014Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, s. 1155-1162Artikel i tidskrift (Refereegranskat)
  • 15.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Reznitskii, Leonid
    Russian Academy of Science, Irkutsk.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Vanadio-oxy-dravite, NaV3(Al4Mg2)(Si6O18)(BO3)3(OH)3O, a new mineral species of the tourmaline supergroup2014Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, s. 218-224Artikel i tidskrift (Refereegranskat)
  • 16.
    Bosi, Ferdinando
    et al.
    Sapienza Università di Roma, Italy.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Fregola, Rosa Anna
    Università di Bari Aldo Moro, Italy.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Crystal chemistry of spinels in the system MgAl2O4-MgV2O4-Mg2VO42016Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 101, s. 580-586Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Eight spinel single-crystal samples belonging to the spinel sensu stricto-magnesiocoulsonite series (MgAl2O4-MgV2O4) were synthesized and crystal-chemically characterized by X‑ray diffraction, electron microprobe and optical absorption spectroscopy. Site populations show that the tetrahedrally coordinated site (T) is populated by Mg and minor Al for the spinel sensu stricto compositions, and only by Mg for the magnesiocoulsonite compositions, while the octahedrally coordinated site (M) is populated by Al, V3+, minor Mg, and very minor amounts of V4+. The latter occurs in appreciable amounts in the Al-free magnesium vanadate spinel, T(Mg)M(Mg0.26V3+1.48V4+0.26)O4, showing the presence of the inverse spinel VMg2O4. The studied samples are characterized by substitution of Al3+ for V3+ and (Mg2++V4+) for 2V3+ described in the system MgAl2O4-MgV2O4-VMg2O4.

    The present data in conjunction with data from the literature provide a basis for quantitative analyses of two solid-solution series MgAl2O4-MgV23+O4 and MgV23+O4-V4+Mg2O4. Unit-cell parameter increases with increasing V3+ along the series MgAl2O4-MgV2O4 (8.085–8.432 Å), but only slightly increases with increasing V3+ along the series VMg2O4-MgV2O4 (8.386–8.432 Å). Although a solid solution could be expected between the MgAl2O4 and VMg2O4 end-members, no evidence was found. Amounts of V4+ are nearly insignificant in all synthetic Al-bearing vanadate spinels, but are appreciable in Al-free vanadate spinel.

    An interesting observation of the present study is that despite the observed complete solid-solution along the MgAl2O4-MgV2O4 and MgV2O4-VMg2O4 series, the spinel structure seems to be unable to stabilize V4+ in any intermediate members on the MgAl2O4-Mg2VO4 join even at high oxygen fugacities. This behavior indicates that the accommodation of specific V-valences can be strongly influenced by crystal-structural constraints, and any evaluation of oxygen fugacities during mineral formation based exclusively on V cation valence distributions in spinel should be treated with caution. The present study underlines that the V valency distribution in spinels is not exclusively reflecting oxygen fugacities, but also depends on activities and solubilities of all chemical components in the crystallization environment.

  • 17.
    Bosi, Ferdinando
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Reznitskii, Leonid
    Russian Academy of Science, Irkutsk.
    Crystallographic and spectroscopic characterization of Fe-bearing chromo-alumino-povondraite and its relationships with oxy-chromium-dravite and oxy-dravite2013Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 98, s. 1557-1564Artikel i tidskrift (Refereegranskat)
  • 18.
    Bruschini, Enrico
    et al.
    Sapienza Università di Roma.
    Speziale, Sergio
    Geoforschungszentrum, Potsdam.
    Andreozzi, Giovanni
    Sapienza Università di Roma.
    Bosi, Ferdinando
    Sapienza Università di Roma.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    The elasticity of MgAl2O4-MnAl2O4 spinels by Brillouin scattering and an empirical approach for bulk modulus prediction2015Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 100, s. 644-651Artikel i tidskrift (Refereegranskat)
  • 19.
    D'Ippolito, Veronica
    et al.
    Sapienza Università di Roma.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Bosi, Ferdinando
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Blue spinel crystals in the MgAl2O4-CoAl2O4 series: I. Flux growth and chemical characterisation2012Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 97, s. 1828-1833Artikel i tidskrift (Refereegranskat)
  • 20.
    Fregola, Rosa Anna
    et al.
    Università di Bari.
    Bosi, Ferdinando
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Cation ordering over short range and long range scales in the MgAl2O4-CuAl2O4 series2012Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 97, s. 1821-1827Artikel i tidskrift (Refereegranskat)
  • 21.
    Fregola, Rosa Anna
    et al.
    University of Bari.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Bosi, Ferdinando
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    D'Ippolito, Veronica
    Sapienza University of Rome.
    Andreozzi, Giovanni
    Sapienza University of Rome.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Optical absorption spectroscopy study of the causes for color variations in natural Fe-bearing gahnite: insights from iron valency and site distribution data.2014Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, s. 2187-2195Artikel i tidskrift (Refereegranskat)
  • 22.
    Gatta, G. Diego
    et al.
    Università di Milano, Italy.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Bosi, Ferdinando
    Sapienza Università di Roma, Italy.
    Canadillas-Delgado, Laura
    Institut Laue-Langevin, Grenoble, France.
    Fernandez-Diaz, Maria Teresa
    Centro Universitario de la Defensa de Zaragoza, Spain.
    Minerals in cement chemistry: A single-crystal neutron diffraction study of ettringite. Ca6Al2(SO4)3(OH)12.27H2O2019Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 104, nr 1, s. 73-78Artikel i tidskrift (Refereegranskat)
  • 23.
    Gatta, G.Diego
    et al.
    Università degli Studi de Milano.
    Bosi, Ferdinando
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    McIntyre, Garry J.
    Australian Nuclear Science and Technology Organisation.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Static positional disorder in ulvöspinel: A single-crystal neutron diffraction study2014Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, s. 255-260Artikel i tidskrift (Refereegranskat)
  • 24.
    Grew, Edward S.
    et al.
    University of Maine.
    Barbier, Jacques
    McMaster University, Ontario.
    Britten, Jim F.
    McMaster University, Ontario.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Shearer, Charles K.
    University of New Mexico.
    The crystal chemistry of welshite, a non-centrosymmetric (P1) aenigmatite-sapphirine-surinamite group mineral2007Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 92, s. 80-90Artikel i tidskrift (Refereegranskat)
  • 25.
    Grew, Edward S.
    et al.
    University of Maine.
    Barbier, Jacques
    McMaster University, Ontario.
    Britten, Jim
    McMaster University, Ontario.
    Yates, Martin G.
    University of Maine.
    Polyakov, Vladislav O.
    Natural Science Museum of the Ilmen State Reserve.
    Shcherbakova, Elena P.
    Natural Science Museum of the Ilmen State Reserve.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Shearer, Charles K.
    University of New Mexico.
    Makarochkinite, Ca2Fe2+4Fe3+Ti4+Si4BeAlO20, a new beryllosilicate member of the aenigmatite-sapphirine-surinamite group from the Il’men Mountains (southern Urals), Russia2005Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 90, s. 1402-1412Artikel i tidskrift (Refereegranskat)
  • 26.
    Grew, Edward S.
    et al.
    University of Maine.
    Locock, Andrew J.
    University of Alberta.
    Mills, Stuart J.
    Museum Victoria.
    Galuskina, Irina O.
    University of Silesia.
    Galuskin, Evgeny V.
    University of Silesia.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Nomenclature of the garnet supergroup2013Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 98, s. 785-811Artikel i tidskrift (Refereegranskat)
  • 27.
    Hålenius, Ulf
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Structural relaxation around Cr3+ and the red-green color change in the spinel s.s.-magnesiochromite (MgAl2O4–MgCr2O4) and gahnite-zincochromite (ZnAl2O4–ZnCr2O4) solid solution series2010Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 95, s. 456-462Artikel i tidskrift (Refereegranskat)
  • 28.
    Hålenius, Ulf
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Bosi, Ferdinando
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Cation ordering in Pb2+-bearing, Mn3+-rich pargasite from Långban, Sweden2012Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 97, s. 1635-1640Artikel i tidskrift (Refereegranskat)
  • 29.
    Hålenius, Ulf
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Bosi, Ferdinando
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Color of Mn-bearing gahnite: A first example of electronic transitions in heterovalent exchange coupled IVMn2+-VIMn3+ pairs in minerals.2014Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, s. 261-266Artikel i tidskrift (Refereegranskat)
  • 30.
    Hålenius, Ulf
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Bosi, Ferdinando
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Gatedal, Kjell
    Nordmark Mining Museum.
    Crystal structure and chemistry of skarn-associated bismuthian vesuvianite2013Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 98, s. 566-573Artikel i tidskrift (Refereegranskat)
  • 31.
    Hålenius, Ulf
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Bosi, Ferdinando
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    A first record of strong structural relaxation of TO4 tetrahedra in a spinel solid solution2011Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 96, s. 617-622Artikel i tidskrift (Refereegranskat)
  • 32.
    Hålenius, Ulf
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Bosi, Ferdinando
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Galaxite, MnAl2O4, a spectroscopic standard for tetrahedrally coordinated Mn2+ in oxygen-based mineral structures2007Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 92, s. 1225-1231Artikel i tidskrift (Refereegranskat)
  • 33.
    Langhof, Jörgen
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Bahfenne, Silmarilly
    Queensland University of Technology.
    Rintoul, Llew
    Queensland University of Technology.
    Frost, Ray L
    Queensland University of Technology.
    Singlecrystal Raman spectroscopy of natural paulmooreite Pb2As2O5 in comparison with the synthesized analog2012Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 97, s. 143-149Artikel i tidskrift (Refereegranskat)
  • 34.
    Reznitskii, Leonid
    et al.
    Russian Academy of Science, Irkutsk, Russia.
    Clark, Christine M.
    University of Manitoba, Winnipeg, Canada.
    Hawthorne, Frank C.
    University of Manitoba, Winnipeg, Canada.
    Grice, Joel D.
    Canadian Museum of Natural History, Ottawa, Canada.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Bosi, Ferdinando
    Sapienza Università di Roma, Rome, Italy.
    Chromo-­alumino-­povondraite,  NaCr3(Al4Mg2)(Si6O18)(BO3)3(OH)3O,  a  new  mineral  species   of  the  tourmaline  supergroup2014Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, s. 1767-1773Artikel i tidskrift (Refereegranskat)
  • 35.
    Scribner, Emily D.
    et al.
    Clemson University, South Caroline, USA.
    Cempírek, Jan
    Masaryk University, Brno, Czech Republic.
    Groat, Lee A
    University of British Columbia; Vancouver, Canada.
    Evans, James
    University of British Columbia, Vancouver, Canada.
    Biagioni, Cristian
    Università di Pisa, Italy.
    Bosi, Ferdinando
    Sapienza Università di Roma, Rome, Italy.
    Dini, Andrea
    Istituto di Geoscienze e Georisorse-CNR, Pisa, Italy.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Orlandi, Paolo
    Università di Pisa, Italy.
    Pasero, Marco
    Università di Pisa, Italy.
    Magnesio-lucchesiite, CaMg3Al6(Si6O18)(BO3)3(OH)3O, a new species of the tourmaline supergroup2021Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 106, nr 6, s. 862-871Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Magnesio-lucchesiite, ideally CaMg3Al6(Si6O18)(BO3)3(OH)3O, is a new mineral species of the tourmaline supergroup. The holotype material was discovered within a lamprophyre dike that cross-cuts tourmaline-rich metapelites within the exocontact of the O’Grady Batholith, Northwest Territories (Canada). Two additional samples were found at San Piero in Campo, Elba Island, Tuscany (Italy) in hydrothermal veins embedded in meta-serpentinites within the contact aureole of the Monte Capanne intrusion. The studied crystals of magnesio-lucchesiite are black in a hand sample with vitreous luster, conchoidal fracture, an estimated hardness of 7–8, and a calculated density of 3.168 (Canada) and 3.175 g/cm3 (Italy). In plane-polarized light, magnesio-lucchesiite is pleochroic (O = dark brown, E = colorless) and uniaxial (–); its refractive index values are nω = 1.668(3) and nε = 1.644(3) (Canada), and nω = 1.665(5) and nε = 1.645(5) (Italy). Magnesio-lucchesiite is trigonal, space group R3m, Z = 3, with a = 15.9910(3) Å, c = 7.2224(2) Å, V = 1599.42(7) Å3 (Canada) and with a = 15.9270(10) Å, c = 7.1270(5) Å, V = 1565.7(2) Å3 (Italy, sample 1). The crystal structure of magnesio-lucchesiite was refined to R1 = 3.06% using 2953 reflections with Fo > 4σ(Fo) (Canadian sample; 1.96% / 1225 for the Italian sample) The Canadian (holotype) sample has the ordered empirical formula X(Ca0.60Na0.39K0.01)Σ1.00Y(Mg2.02Fe2+0.62

    Fe3+0.09Ti0.25V0.01Cr0.01)Σ3.00Z(Al5.31Fe3+0.69)

    Σ6.00[T(Si5.98Al0.02)Σ6.00O18(BO3)3V[(OH)2.59O0.41]

    Σ3.00W(O0.78F0.22)Σ1.00. The Italian (co-type) material shows a wider chemical variability, with two different samples from the same locality having ordered chemical formulas: X(Ca0.88Na0.12)Σ1.00Y(Mg1.45Fe2+0.40Al0.79

    Fe3+0.36)Σ3.00ZAl6[T(Si5.05Al0.95)Σ6.00O18](BO3)3V[(OH)2.90O0.10]Σ3.00W(O0.98F0.02)Σ1.00

    (sample 1) and X(Ca0.71Na0.21o0.08)Σ1.00Y(Mg2.49

    Fe2+0.41Ti0.10)Σ3.00Z(Al5.44Fe3+0.46Mg0.09V0.01)

    Σ6.00[T(Si5.87Al0.13)Σ6.00O18](BO3)3V(OH)3W[O0.61(OH)0.39]Σ1.00 (sample 2). Magnesio-lucchesiite is an oxy-species belonging to the calcic group of the tourmaline supergroup. It is related to lucchesiite by the homovalent substitution YFe ↔ YMg, and to feruvite by the homovalent and heterovalent substitutions YFe ↔ YMg and ZAl3+ + WO2–ZMg2+ + W(OH)1–. The new mineral was approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA 2019-025). Occurrences of magnesio-lucchesiite show that its presence is not restricted to replacement of mafic minerals only; it may also form in metacarbonate rocks by fluctuations of F and Al during crystallization of common uvitic tourmaline. High miscibility with other tourmaline end-members indicates the large petrogenetic potential of magnesio-lucchesiite in Mg,Al-rich calc-silicate rocks, as well as contact-metamorphic and metasomatic rocks.

  • 36.
    Skogby, Henrik
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hålenius, Ulf
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kristiansson, Per
    Lunds universitet.
    Ohashi, Harou
    Hashi Institute for Silicate Science, Tokyo.
    Ti-incorporation and VITi3+-IVTi4+ intervalence charge transfer in Na and Ti substituted diopside2006Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 91, s. 1794-1801Artikel i tidskrift (Refereegranskat)
  • 37. Stalder, Roland
    et al.
    Potrafke, Alexander
    Billström, Kjell
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Meinhold, Guido
    Gögele, Christian
    Berberich, Thomas
    OH defects in quartz as monitor for igneous, metamorphic, and sedimentary processes2017Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 102, s. 1832-1842Artikel i tidskrift (Refereegranskat)
  • 38. Ward, D.
    et al.
    Bischoff, A.
    Roszjar, J.
    Berndt, J.
    Whitehouse, Martin J.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Trace element inventory of meteoritic Ca-phosphates.2017Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 102, s. 1856-1880Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Most extraterrestrial samples feature the two accessory Ca-phosphates (apatite-group minerals and merrillite), which are important carrier phases of the rare earth elements (REE). The trace-element concentrations (REE, Sc, Ti, V, Cr, Mn, Co, As, Rb, Sr, Y, Zr, Nb, Ba, Hf, Ta, Pb, Th, and U) of selected grains were analyzed by LA-ICP-MS and/or SIMS (REE only). This systematic investigation includes 99 apatite and 149 merrillite analyses from meteorites deriving from various asteroidal bodies including 1 carbonaceous chondrite, 8 ordinary chondrites, 3 acapulcoites, 1 winonaite, 2 eucrites, 5 shergottites, 1 ureilitic trachyandesite, 2 mesosiderites, and 1 silicate-bearing IAB iron meteorite.Although Ca-phosphates predominantly form in metamorphic and/or metasomatic reactions, some are of igneous origin. As late-stage phases that often incorporate the vast majority of their host’s bulk REE budget, the investigated Ca-phosphates have REE enrichments of up to two orders of magnitude compared to the host rock’s bulk concentrations. Within a single sample, each phosphate species displays a uniform REE-pattern, and variations are mainly restricted to their enrichment, therefore indicating similar formation conditions. Exceptions are brecciated samples, i.e., the Adzhi-Bogdo (LL3-6) ordinary chondrite. Despite this uniformity within single samples, distinct meteorite groups do not necessarily have unique REE-patterns. Four basic shapes dominate the REE patterns of meteoritic Ca-phosphates: (1) flat patterns, smoothly decreasing from La-Lu with prominent negative Eu anomalies (acapulcoites, eucrites, apatite from the winonaite and the ureilitic trachyandesite, merrillite from ordinary chondrites); (2) unfractionated patterns, with only minor or no anomalies (mesosiderites, enriched shergottites, IAB-iron meteorite); (3) LREE-enriched patterns, with either positive or slightly negative Eu anomalies (chondritic apatite); and (4) strongly LREE-depleted patterns, with negative Eu anomalies (depleted shergottites). The patterns do not correlate with the grade of metamorphism (petrologic type), specific adjacent mineral assemblages or with Ca-phosphate grain size. Neither the proportions of different REE, nor particular REE patterns themselves are universally correlated to a specific formation mechanism yet Eu (i.e., magnitude of the Eu anomaly) is a sensitive indicator to evaluate the timing of plagioclase and phosphate crystallization. Based on our data, U and Th abundances in apatite increase (almost linearly) with the grade of metamorphism, as well as with the differentiation of their host rock.

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  • 39.
    Watenphul, Anke
    et al.
    University of Hamburg.
    Schlüter, Jochen
    University of Hamburg.
    Bosi, Ferdinando
    University of Rome "La Sapienza".
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Malcherek, Thomas
    University of Hamburg.
    Influence of the octahedral cationic-site occupancies on the framework vibrations of Li-free tourmalines, with implications for estimating temperature and oxygen fugacity in host rocks2016Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 101, s. 2554-2563Artikel i tidskrift (Refereegranskat)
  • 40.
    Weis, Franz
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Stalder, Roland
    University of Innsbruck.
    Skogby, Henrik
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Experimental hydration of natural volcanic clinopyroxene phenocrysts under hydrothermal pressures (0.5 – 3 kbar)2016Ingår i: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 101, s. 2233-2247Artikel i tidskrift (Refereegranskat)
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    fulltext
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