Ferrirockbridgeite, (Fe0.673+□0.33)2(Fe3+)3(PO4)3(OH)4(H2O), and the oxidation (Fe 3+mechanism for rockbridgeite-group minerals

被引:3
作者
Grey, Ian Edward [1 ]
Kampf, Anthony R. [2 ]
Keck, Erich [3 ]
Cashion, John D. [4 ]
MacRae, Colin M. [1 ]
Gozukara, Yesim [5 ]
Shanks, Finlay L. [6 ]
机构
[1] CSIRO Mineral Resources, Private Bag 10, Clayton, Vic 3169, Australia
[2] Nat Hist Museum Los Angeles Cty, Mineral Sci Dept, 900 Exposit Blvd, Los Angeles, CA 90007 USA
[3] Algunderweg 3, D-92694 Etzenricht, Germany
[4] Monash Univ, Sch Phys & Astron, Clayton, Vic 3800, Australia
[5] CSIRO Mfg, Private Bag 10, Clayton, Vic 3169, Australia
[6] Monash Univ, Sch Chem, Clayton, Vic 3800, Australia
关键词
ferrirockbridgeite; new mineral; rockbridgeite group; oxidation mechanism; crystal structure; Mossbauer; PSEUDORUTILE; VACANCIES;
D O I
10.1127/ejm/2019/0031-2846
中图分类号
P57 [矿物学];
学科分类号
070901 ;
摘要
Ferrirockbridgeite, ideally (Fe-0.67(3+)square(0.33))(2)(Fe3+)(3)(PO4)(3)(OH)(4)(H2O), is a new member of the rockbridgeite group. The type specimen is from the Palermo No. 1 pegmatite in North Groton, Grafton County, New Hampshire, USA. Electron microprobe analysis, coupled with Mossbauer spectroscopy for FeO and thermogravimetric analysis (TGA) for H2O gives the empirical formula Mn2o3 Fe2o-PosMgo oiZno 03Cao 05Fe43 P - 2 87017146 H. Ferrirockbridgeite is orthorhombic, space group Bbmm with a = 13.853(1), b = 16.928(1), c = 5.1917(5) angstrom and Z = 4. Optically, ferrirockbridgeite is biaxial (-), with alpha = 1.875(5), beta = 1.890(calc), gamma = 1.900(5) (measured in white light) and 2V (meas) is 78(1) from extinction data. The dispersion is strong, with r > v. The optical orientation is X = c, Y = a, Z = b. The pleochroism is X = yellow brown, Y = olive brown, Z = dark olive green; Z > Y > X. Crystal structure refinements on ferrirockbridgeite and other oxidized rockbridgeite-group species, including type rockbridgeite and type frondelite, show that oxidation is accompanied by loss of Fe2+ from the M2 site according to the reaction [3Fe2+] -> [2Fe3+ + LI] + Fe2+(removed) + 2e-. A variable portion of the Fe removed from the M2 site becomes trapped at M3 site vacancies. A general formula for oxidized rockbridgeite-group minerals is presented.
引用
收藏
页码:585 / 594
页数:10
相关论文
共 25 条
[1]  
[Anonymous], 1990, SATELLITE M POWDER D
[2]   Description and crystal structure of a new mineral - plimerite, ZnFe43+(PO4)3(OH)5 - the Zn-analogue of rockbridgeite and frondelite, from Broken Hill, New South Wales, Australia [J].
Elliott, P. ;
Kolitsch, U. ;
Giester, G. ;
Libowitzky, E. ;
McCammon, C. ;
Pring, A. ;
Birch, W. D. ;
Brugger, J. .
MINERALOGICAL MAGAZINE, 2009, 73 (01) :131-148
[3]  
FRONDEL C, 1949, AM MINERAL, V34, P513
[4]   Comprehensive derivation of bond-valence parameters for ion pairs involving oxygen [J].
Gagne, Olivier Charles ;
Hawthorne, Frank Christopher .
ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE CRYSTAL ENGINEERING AND MATERIALS, 2015, 71 :562-578
[5]   The rockbridgeite group approved and a new member, ferrorockbridgeite, (Fe2+,Mn2+)2(Fe3+)3(PO4)3(OH)4(H2O), described from the Hagendorf Sud pegmatite, Oberpfalz, Bavaria [J].
Grey, Ian E. ;
Kampf, Anthony R. ;
Keck, Erich ;
Cashion, John D. ;
MacRae, Colin M. ;
Gozukara, Yesim ;
Peterson, Vanessa K. ;
Shanks, Finlay L. .
EUROPEAN JOURNAL OF MINERALOGY, 2019, 31 (02) :389-397
[6]   Non-stoichiometry and local order in minerals with the rockbridgeite structure [J].
Grey, Ian Edward ;
Williams, Tim ;
Kampf, Anthony R. ;
Cashion, John D. ;
Gozukara, Yesim ;
MacRae, Colin M. ;
Keck, Erich .
EUROPEAN JOURNAL OF MINERALOGY, 2018, 30 (04) :773-783
[7]   Hydroxylian pseudorutile derived from picroilmenite in the Murray Basin, southeastern Australia [J].
Grey, IE ;
Li, C .
MINERALOGICAL MAGAZINE, 2003, 67 (04) :733-747
[8]  
GREY IE, 1975, AM MINERAL, V60, P898
[9]  
Gunter Mickey E., 2004, Microscope, V52, P23
[10]   Existence of Superstructures Due to Large Amounts of Fe Vacancies in the LiFePO4-Type Framework [J].
Hamelet, S. ;
Casas-Cabanas, M. ;
Dupont, L. ;
Davoisne, C. ;
Tarascon, J. M. ;
Masquelier, C. .
CHEMISTRY OF MATERIALS, 2011, 23 (01) :32-38