Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-12T22:00:32.920Z Has data issue: false hasContentIssue false
  • English
  • Français

Fluoro-aluminoleakeite, NaNa2(Mg2Al2Li)Si8O22F2, a new mineral of the amphibole group from Norra Kärr, Sweden: description and crystal structure

Published online by Cambridge University Press:  05 July 2018

R. Oberti ,
F. Cámaraite ,
F. C. Hawthorne  and
N. A. Ball
R. Oberti*
Affiliation:
CNR-Istituto di Geoscienze e Georisorse, unita di Pavia, via Ferrata 1, I-27100 Pavia, Italy
F. Cámaraite
Affiliation:
CNR-Istituto di Geoscienze e Georisorse, unita di Pavia, via Ferrata 1, I-27100 Pavia, Italy
F. C. Hawthorne
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
N. A. Ball
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
*
* E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Fluoro-aluminoleakeite, ideally , is a new mineral of the amphibole group from Norra Kärr, Sweden (IMA-CNMMNC 2009-012). It occurs in a proterozoic alkaline intrusion that mainly comprises a fine-grained schistose agpaitic nepheline-syenite (grennaite). Fluoro- aluminoleakeite occurs as isolated prismatic crystals 0.10–2 mm long in a syenitic matrix. Crystals are light greenish-blue with a greenish-blue streak. It is brittle, has a Mohs hardness of 6 and a splintery fracture; it is non-fluorescent with perfect {110} cleavage, no observable parting, and has a calculated density of 3.14 g cm–3. In plane-polarized light, it is pleochroic, X = pale green, Y = dark green, Z = pale green; X ^ a = 62.9° (in β obtuse), Y || b. Fluoro-aluminoleakeite is biaxial negative, α = 1.632(1), β = 1.638(1), γ = 1.643(1); 2Vobs. = 98.0(4)°, 2Vcalc. = 95.5°.M

Fluoro-aluminoleakeite is monoclinic, space group C2/m, a = 9.7043(5) Å, b = 17.7341(8) Å, c = 5.2833(3) Å, β = 104.067(4)°, V = 882.0(2) Å3, Z = 2. The eight strongest X-ray diffraction lines in the powder-diffraction pattern are [d in Å, (I), (hkl)]: 2.687, (100), (31, 151); 4.435, (80), (021, 040); 3.377, (80), (131); 2.527, (60), (02); 8.342, (50), (110); 3.096, (40), (310); 2.259, (40), (71, 12) and 2.557, (30), (002, 061). Analysis, by a combination of electron microprobe and crystal-structure refinement, gives SiO2 58.61, Al2O3 7.06, TiO2 0.32, FeO 3.27, Fe2O3 6.05, MgO 8.61, MnO 0.73, ZnO 0.43, CaO 0.05, Na2O 9.90, K2O 2.43, Li2O 1.62, F 3.37, H2Ocalc. 0.50, sum 101.08 wt.%. The formula unit, calculated on the basis of 24 (O,OH,F,Cl) p.f.u. with (OH) + F = 2 a.p.f.u., is A(Na0.65 O22W(F1.47OH0.53)Σ=2.00. Crystal-structure analysis shows CLi to be completely ordered at the M(3) site, and provided reliable site populations. Fluoro-aluminoleakeite is related to the end-member leakeite, , by the substitutions CFe3+ → CAl and WF → W(OH).

Keywords

Fluoro-aluminoleakeitenew amphibolelithiumelectron microprobe analysisoptical propertiescrystal-structure refinementNorra KärrSweden.
Type
Research Article
Information
Mineralogical Magazine , Volume 73 , Issue 5 , October 2009 , pp. 817 - 824
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Adamson, O.J. (1942) Eckermannite, a new alkali amphibole. Geo/ogiska FOreningens i Stockholm FOrhand/ingar, 64, 329—334.Google Scholar
Adamson, O.J. (1944) The petrology of the Nora Karr district. Geo/ogiska Foreningens i Stockho/m Forhand/ingar, 66, 113—255.Google Scholar
Armbruster, T., Oberhansli, R., Bermanec, V. and Dixon, R. (1993) Hennomartinite and kornite: two new Mn3+ rich silicates from the Wessels Mine, Kalahari, South Africa. Schweizerische Minera/ogische und Petrographische Mittei/ungen, 73, 349—355.Google Scholar
Bartelmehs, K.L., Bloss, F.D., Downs, R.T. and Birch, J.B. (1992) Excalibr II. Zeitschrift für Krista//ographie, 199, 185–196.CrossRefGoogle Scholar
Blaxland, A.B. (1977) Agpaitic magmatism at Norra Karr? Rb-Sr isotopic evidence. Lithos, 10, 1—8.CrossRefGoogle Scholar
Della Ventura, G., Redhammer, G.J., Iezzi, G., Hawthorne, F.C., Papin, A. and Robert, J.L. (2005). A Mossbauer and FTIR study of synthetic amphiboles along the magnesioriebeckite-ferri-clinoholm- quistite join. Physics and Chemistry of Minera/s, 32, 103—113.Google Scholar
Fleischer, M. (1944) New mineral names. American Minera/ogist, 29, 455—456.Google Scholar
Ginsburg, I.V. (1965) Holmquistite and its structural variety clinoholmquistite. Trudy, Minera/ogicheskiy Muzeya Akademiya Nauk SSSR, 16, 73—89.Google Scholar
Hawthorne, F.C., Oberti, R., Ungaretti, L. and Grice, J.D. (1992) Leakeite, NaNa2(Mg2Al2Li)Si8O22F2, a new amphibole from the Kajlidongri manganese mine, Jhabua district, Madhya Pradesh, India. American Mineralogist, 77, 1112–1115.Google Scholar
Hawthorne, F.C., Ungaretti, L., Oberti, R., Bottazzi, P. and Czamanske, G.K. (1993) Li: an important component in igneous alkali amphiboles. American Mineralogist, 78, 733–745.Google Scholar
Hawthorne, F.C., Ungaretti, L., Oberti, R. and Cannillo, E. (1994) The mechanism of [6]Li incorporation in amphiboles. American Mineralogist, 79, 443–451.Google Scholar
Hawthorne, F.C., Oberti, R. and Sardone, N. (1996) Sodium at the A site in clinoamphiboles: the effects of composition on patterns of order. The Canadian Mineralogist, 34, 577–593.Google Scholar
Holtstam, D. (1998) Jinshajiangite from the Norra Karr alkaline intrusion, Jonkoping, Sweden. Geologiska Foreningens i Stockholm Forhandlingar, 120, 373–374.Google Scholar
Iezzi, G., Della Ventura, G., Cámaraite, F., Pedrazzi, G. and Robert, J.L. (2003). BNa-BLi solid-solution in A- site vacant amphiboles: synthesis and cation ordering along the ferri-clinoferroholmquistite-riebeckite join. American Mineralogist, 88 955–961.CrossRefGoogle Scholar
Kramm, U. and Koark, H.J. (1988) Isotopic composition of galena lead from the Norra Karr peralkaline complex, Sweden. Geologiska Foreningens i Stockholm Forhandlingar, 110, 311–316 CrossRefGoogle Scholar
Oberti, R., Cámaraite, F., Ottolini, L. and Caballero, J.M. (2003a) Lithium in amphiboles: detection, quantification, and incorporation mechanisms in the compositional space bridging sodic and BLi-amphi- boles. European Journal of Mineralogy, 15, 309–319.CrossRefGoogle Scholar
Oberti, R., Boiocchi, M. and Smith, D.C. (2003b) Fluoronyboite from Jianchang (Su-Lu, China) and nyboite from Nybo (Nordfjord, Norway): description and comparison of two high-pressure amphibole end- members. Mineralogical Magazine, 67, 769–782.CrossRefGoogle Scholar
Oberti, R., Cámaraite, F. and Ottolini, L. (2005) Clinoholmquistite discredited: The new amphibole end-member fluoro-sodic-pedrizite. American Mineralogist, 90, 732–736.CrossRefGoogle Scholar
Oberti, R., Hawthorne, F.C., Cannillo, E. and Cámaraite, F. (2007) Long-range order in amphiboles. Pp. 125-172 in: Amphiboles: Crystal Chemistry, Occurrence and Health Issues (F.C. Hawthorne, R. Oberti, G. Della Ventura and A. Mottana, editors). Reviews in Mineralogy and Geochemistry, 67, Mineralogical Society of America, Chantilly, Virginia, USA.Google Scholar
Oberti, R., Boiocchi, M., Ball, N.A. and Hawthorne, F.C. (2009) Fluoro-sodic-ferropedrizite, NaLi2(Fe2+Al2Li)Si8O22F2, a new mineral of the amphibole group from the Sutlug River, Tuva Republic, Russia: Description and crystal structure. Mineralogical Magazine, 73 , 487–494.CrossRefGoogle Scholar
Pouchou, J.L. and Pichoir, F. (1985) ‘PAP’ j(pZ) procedure for improved quantitative microanalysis. Pp. 104-106 in: Microbeam Analysis (J.T. Armstrong, editor). San Francisco Press, San Francisco, California, USA.Google Scholar
Sundius, N. (1945) The composition of eckermannite and its position in the amphibole group. Arsbok Sveriges Geologiska UndersOkning, 39 (8), 3–7.Google Scholar
Tait, K.T., Hawthorne, F.C., Grice, J.D., Ottolini, L. and Nayak, V.K. (2005) Dellaventuraite, NaNa2(Mg2Al2Li)Si8O22F2, a new anhydrous amphibole from the Kajlidongri Manganese Mine, Jhabua District, Madhya Pradesh, India. American Mineralogist, 90, 304–309.CrossRefGoogle Scholar
von Eckermann, C.W. (1968) New contributions to the interpretation of the genesis of the Norra Karr alkaline body in Southern Sweden, Lithos, 1, 76–88.CrossRefGoogle Scholar
Supplementary material: File

Oberti et al. supplementary material

Structure factor data

Download Oberti et al. supplementary material(File)
File 94.2 KB
Supplementary material: File

Oberti et al. supplementary material

Cif file

Download Oberti et al. supplementary material(File)
File 20.3 KB