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leakeite group

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Difference-Fourier maps calculated for the  A -<span class="search-highlight">group</span> sites in <span class="search-highlight">leakeite</span> (a; ...
Published: 01 December 2003
F ig . 1. Difference-Fourier maps calculated for the A -group sites in leakeite (a; sample A2 in Hawthorne et al . 1994 ), ferriwhittakerite and ferri-ottoliniite (b and c; Oberti et al . 2004 ), sodic-ferri-ferropedrizite and ferri-clinoferroholmquistite (d and e; this work). Right
Journal Article
Published: 01 February 1996
American Mineralogist (1996) 81 (1-2): 226–228.
... , Z ∧ a = 4° (in β obtuse), with absorption X > Y > Z . Fluor-ferro-leakeite is biaxial positive, α = 1.675(2), β = 1.683(2), γ = 1.694(1); 2 V = 87(2)°; dispersion is not visible because of the strong absorption. Fluor-ferro-leakeite is monoclinic, space group C 2/ m , a = 9.792(1), b = 17.938...
Journal Article
Published: 01 June 2017
Mineralogical Magazine (2017) 81 (3): 707–722.
...Roberta Oberti; Giancarlo Della Ventura; Massimo Boiocchi; Alberto Zanetti; Frank C. Hawthorne Abstract New chemical (EMP, SIMS) and structural data are reported for a suite of crystals of oxo-mangani-leakeite and mangano-mangani-ungarettiite from their common type locality, the Hoskins mine (New...
FIGURES
Journal Article
Published: 01 October 2016
Mineralogical Magazine (2016) 80 (6): 1013–1021.
... and characterization of a new member of the oxo-amphiboles group, i.e. oxo-mangani-leakeite. In a second paper ( Oberti et al. , 2017 ), we will report on the crystal-chemistry of Li in oxo amphiboles and on the apparent solvus between mangano-mangani-ungarettiite and oxo-mangani-leakeite (plus oxo-bearing leakeites...
FIGURES
Journal Article
Published: 01 July 2002
American Mineralogist (2002) 87 (7): 976–982.
... maintained in the rest of the Mg-Fe-Mn-Li group. Complete solid solution between ferripedrizite and leakeite [ideally, A Na B Na 2 C (Fe 3+ 2 Mg 2 Li) T Si 8 O 22 X (OH) 2 ] has been found in the Pedriza Massif. According to the present nomenclature rules, this join bridges three different amphibole groups...
FIGURES
Journal Article
Published: 01 October 1992
American Mineralogist (1992) 77 (9-10): 1112–1115.
... > Z. Leakeite is biaxial negative, α = 1.667(1), α = 1.675(1), γ = 1.691(1); 2 V = 59–71°, dispersion strong r ≪ v . It is monoclinic, space group C 2/ m, a = 9.822(3), b = 17.836(6), c = 5.286(2) Å, β = 104.37(3)°, V : 897.1(5) Å 3 , Z = 2. The strongest ten X-ray diffraction lines in the powder...
Journal Article
Published: 01 June 2010
Mineralogical Magazine (2010) 74 (3): 521–528.
...). Fluoroleakeite is biaxial negative, α = 1.663(2), β = 1.673(2), γ = 1.680(2); 2V obs = 80.9(6)°, 2V calc = 79.4° Fluoro-leakeite is monoclinic, space group C 2/ m , a = 9.8927(3), b = 17.9257(6), c = 5.2969(2) Å, β = 103.990(1)°, V = 905.7(1) Å 3 , Z = 2. The strongest ten X-ray diffraction lines in the powder...
Journal Article
Published: 01 March 2017
European Journal of Mineralogy (2017) 29 (1): 143–148.
... ). Data were processed using SAINT ( Bruker, 1999 ). An empirical absorption correction using SADABS ( Sheldrick, 1996 ) was applied. The correct space group was C 2/ m , in agreement with other amphiboles belonging to the compositional space of leakeite. The structures were solved by direct methods...
FIGURES
Journal Article
Published: 01 August 2016
Russ. Geol. Geophys. (2016) 57 (8): 1191–1203.
... in these minerals were considered in detail by Hawthorne et al. ( Hawthorne, 1983 ; Hawthorne et al., 1992 , 1993 , 1994 , 1996a , b , 2001 ). According to the latest nomenclature of the amphibole supergroup, all Na–Li members are combined into the leakeite group (Na-amphibole subgroup) ( Hawthorne et al...
FIGURES | View All (6)
Journal Article
Published: 25 March 2021
The Canadian Mineralogist (2021) 59 (2): 431–444.
..., Kalahari manganese field, South Africa. Both minerals occur as brown radiating groups or aggregates of acicular or prismatic crystals, with individual crystals up to 0.15 × 0.04 × 0.02 mm for taniajacoite and 1.3 × 0.2 × 0.2 mm for strontioruizite. Minerals associated with taniajacoite include sugilite...
FIGURES | View All (8)
Journal Article
Published: 01 March 2000
American Mineralogist (2000) 85 (3-4): 578–585.
... in the M4 cavity and at the M3 site. Thus, sodic-ferripedrizite encompasses the different site-preferences and crystal-chemical mechanisms observed for Li in amphiboles of the Mg-Fe-Mn-Li group (clinoholmquistite series) and the Na-Ca group (leakeite series). These data and other recent results on synthetic...
FIGURES
Journal Article
Published: 01 March 2003
European Journal of Mineralogy (2003) 15 (2): 309–319.
...: leakeite, kornite, whittakerite and pedrizite) have more than half-occupied A-group sites. Seven new amphibole end-members containing lithium have been discovered in epysienites (dequartzified and albitised granites) from the Pedriza Massif (Central Spain), where lithium incorporation and partitioning...
FIGURES | View All (5)
Journal Article
Published: 01 October 2009
Mineralogical Magazine (2009) 73 (5): 817–824.
... [root composition Li 2 (Mg 3 Al 2 )Si 8 O 22 (OH) 2 ] and in clinoholmquistite ( Ginsburg, 1965 ); however, the latter was recently discredited by Oberti et al . ( 2005 ). C -group Li, strongly ordered at the M (3) site, was first identified as a major constituent in leakeite [ A Na B Na 2 C...
Journal Article
Published: 01 February 2005
American Mineralogist (2005) 90 (2-3): 304–309.
... et al. 1995 ), and obertiite, NaNa 2 2+ (Mg 3 Fe 3+ Ti 4+ )Si 8 O 22 O 2 ( Hawthorne et al. 2000 ). Dellaventuraite is the eighth amphibole containing essential Li as a C-group cation. The others are as follows: leakeite, NaNa 2 (Mg 2 Fe 2 3+ Li) Si 5 O 22 (OH) 2 ( Hawthorne et al. 1992...
FIGURES
Journal Article
Published: 01 June 1994
American Mineralogist (1994) 79 (5-6): 443–451.
...-radiation; the crystals used in the collection of the X-ray data were subsequently analyzed by electron microprobe techniques. Both site-scattenng refinement and an ion microprobe analysis show major Li in these crystals (up to ~1.3 wt% Li 2 O), which fall in the series ferri-eckermannite-leakeite [ NaNa 2...
Journal Article
Published: 01 August 2014
Mineralogical Magazine (2014) 78 (4): 861–869.
...R. Oberti; M. Boiocchi; F. C. Hawthorne; R. Kristiansen Abstract A second occurrence of ferri-fluoro-leakeite has been identified in the Bratthagen nepheline syenite pegmatite (Vestfold County, Norway). With respect to the holotype found at the Verkhnee Espe deposit (Akjailyautas Mountains...
FIGURES
Journal Article
Published: 01 April 2015
American Mineralogist (2015) 100 (4): 909–914.
...Roberta Oberti; Massimo Boiocchi; Frank C. Hawthorne; Neil A. Ball; George E. Harlow Abstract Following the characterization of the new amphibole species fluoro-leakeite, ideally A Na B Na 2 C (Mg 2 Al 2 Li) T Si 8 O 22 W F 2 , at Norra Kärr (Sweden), so far considered the type locality...
FIGURES
Journal Article
Published: 01 October 2007
Reviews in Mineralogy and Geochemistry (2007) 67 (1): 55–88.
.... 2005 ) discredits the use of Schaller modifiers. Hence we suggest using expressions of the type Cl-rich or Cl-bearing preceding the root-name. © The Mineralogical Society Of America 2007 Classification is always a highly contentious issue, particular when dealing with a group...
FIGURES | View All (14)
Journal Article
Published: 01 February 2006
The Canadian Mineralogist (2006) 44 (1): 1–21.
... chemical variables used in a classification procedure, and (6) the use of the dominant-constituent principle. The current IMA-approved classification scheme is based on the A , B and T groups of cations in the amphibole formula: AB 2 C 5 T 8 O 22 W 2 . We argue here that classification should be based...
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Journal Article
Published: 01 March 2017
American Mineralogist (2017) 102 (3): 694–698.
...; 3 ¯ 31 ), 2.575 (24; 061), 2.331 (24; 3 ¯ 51 , 4 ¯ 21 ). Single-crystal X-ray diffraction data collected on a crystal of size 200 × 50 × 50 μm refined to R 1 = 0.0201 for 769 unique reflections with I ≥ 3σ( I ) shows oxo-mangani-leakeite is monoclinic, space group C...