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The crystal chemistry of ‘wheatsheaf’ tourmaline from Mogok, Myanmar

Published online by Cambridge University Press:  05 July 2018

A. J. Lussier ,
F. C. Hawthorne ,
Y. Abdu ,
S. Herwig ,
V. K. Michaelis ,
P. M. Aguiar  and
S. Kroeker
A. J. Lussier
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
F. C. Hawthorne*
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
Y. Abdu
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
S. Herwig
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
V. K. Michaelis
Affiliation:
Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
P. M. Aguiar
Affiliation:
Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
S. Kroeker
Affiliation:
Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
*
*E-mail: frank_hawthorne@umanitoba.ca
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Abstract

Tourmalines of unusual (mushroom) habit are common in granitic pegmatites of Momeik, northeast of Mogok, Myanmar. Here, we examine a sample of elbaite of significantly different habit, consisting of a series of diverging crystals, resembling a sheaf of wheat and ranging in colour from light purplish-red at the base to dark purplish-red at the tip with a thin green cap at the termination. The crystal structures of eight crystals are refined to R1-indices of ∼2.5% using graphite-monochromated Mo-Kα X-radiation; the same crystals were analysed by electron microprobe. 11B and 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra were collected on four regions of the wheatsheaf crystal, and show ∼0.3 a.p.f.u. [4]B and <0.1 a.p.f.u. [4]Al in the structure. 57Fe Mössbauerspectr oscopy was done on the dark green rim at the termination of the crystal, showing all Fe in this region (∼0.6 a.p.f.u.) to be Fe2+. Detailed electron-microprobe traverses show that the principal compositional variation involves the substitutions [4]B + YAl → Si + YFe*, where transition metals are present, and [4]B2 + YAl → Si2 + YLi, where transition metals are not present, although several other minor substitutions also affect crystal composition. Successive microscopic bifurcation of crystallites causes divergence of growth directions along the c axis, imparting the overall ‘wheatsheaf’ shape to the crystal aggregate. We suggest that such bifurcation is common in pegmatitic elbaite crystals, resulting in their common divergent habit.

Keywords

elbaiteMogokMyanmarwheatsheafEPMAMössbauerspectr oscopySEMMAS-NMR spectroscopy
Type
Research Article
Information
Mineralogical Magazine , Volume 75 , Issue 1 , February 2011 , pp. 65 - 86
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2011

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References

Andreozzi, G.B., Bosi, F. and Longo, M. (2008) Linking Mössbauer and structural parameters in elbaiteschorl-dravite tourmalines. American Mineralogist, 93, 658–666.CrossRefGoogle Scholar
Aurisicchio, C., Ottolini, L. and Pezzotta, F. (1999) Electron- and ion-microprobe analyses, and genetic inferences of tourmalines of the foitite-schorl solid solution. European Journal of Mineralogy, 11, 217–225.CrossRefGoogle Scholar
Barley, M., Pickard, A.L. and Zaw, K. (2003) Jurassic to Miocene magmatism and metamorphism in the Mogok metamorphic belt and the India-Eurasia collision in Myanmar. Tectonics, 22, 1019–1031.CrossRefGoogle Scholar
Bloodaxe, E.S., Hughes, J.M., Dyar, M.D., Grew, E.S. and Guidotti, C.V. (1999) Linking structure and chemistry in the schorl-dravite series. American Mineralogist, 84, 922–928.CrossRefGoogle Scholar
Bosi, F. (2008) Disordering of Fe2+ overoctahedr ally coordinated sites of tourmaline. American Mineralogist, 93, 1647–1653.CrossRefGoogle Scholar
Bosi, F. and Lucchesi, S. (2004) Crystal chemistry of the schorl-dravite series. European Journal of Mineralogy, 16, 335–344.CrossRefGoogle Scholar
Bosi, F. and Lucchesi, S. (2007) Crystal chemistry in the tourmaline group: Structural constraints on chemical variability. American Mineralogist, 92, 1054–1063.CrossRefGoogle Scholar
Bosi, F., Andreozzi, G.B., Federico, M., Graziani, G. and Lucchesi, S. (2005) Crystal chemistry of the elbaite-schorl series. American Mineralogist, 90, 1784–1792.CrossRefGoogle Scholar
Bosi, F., Lucchesi, S. and Reznitskii, L. (2004) Crystal chemistry of the dravite–chromdravite series. European Journal of Mineralogy, 16, 345–352.CrossRefGoogle Scholar
Bray, P.J. (1999) NMR and NQR studies of boron in vitreous and crystalline borates. Inorganica Chimica Acta, 289, 158–173.CrossRefGoogle Scholar
Burns, P.C., Macdonald, D.J. and Hawthorne, F.C. (1994) The crystal chemistry of manganese-bearing elbaite. The Canadian Mineralogist, 32, 31–41.Google Scholar
Cámara, F., Ottolini, L. and Hawthorne, F.C. (2002) Crystal chemistry of three tourmalines by SREF, EMPA, and SIMS. American Mineralogist, 87, 1437–1442.CrossRefGoogle Scholar
Dyar, M.D., Taylor, M.E., Lutz, T.M., Francis, C.A., Robertson, J.D., Cross, L.M., Guidotti, C.V. and Wise, M. (1998) Inclusive chemical characterization of tourmaline: Mössbauerstudy of Fe valence and site occupancy. American Mineralogist, 83, 848–864.CrossRefGoogle Scholar
Ertl, A. and Hughes, J.M. (2002) The crystal structure of an aluminum-rich schorl overgrown by boron-rich olenite from Koralpe, Styria, Austria. Mineralogy and Petrology, 75, 69–78.CrossRefGoogle Scholar
Ertl, A., Hughes, J.M., Brandstätter, F., Dyar, M.D. and Prasad, P.S.R. (2003a) Disordered Mg-bearing olenite from a granitic pegmatite from Goslarn, Austria: A chemical, structural, and infrared spectroscopic study. The Canadian Mineralogist, 41, 1363–1370.CrossRefGoogle Scholar
Ertl, A., Hughes, J.M., Prowatke, S., Rossman, G.R., London, D. and Fritz, E.A. (2003b) Mn-rich tourmaline from Austria: structure, chemistry, optical spectra, and relations to synthetic solid solutions. American Mineralogist, 88, 1369–1376.CrossRefGoogle Scholar
Ertl, A., Pertlik, F., Dyar, M.D., Prowatke, S., Hughes, J.M., Ludwig, T. and Bernhardt, H.-J. (2004) Fe-rich olenite with tetrahedrally coordinated Fe3+ from Eibenstein, Austria: Structural, chemical, and Mössbauerdata. The Canadian Mineralogist, 42, 1057–1063.CrossRefGoogle Scholar
Ertl, A., Rossman, G.R., Hughes, J.M., Prowatke, S. and Ludwig, T. (2005) Mn-bearing “oxy-rossmanite” with tetrahedrally coordinated Al and B from Austria: Structure, chemistry, and infrared and optical spectroscopic study. American Mineralogist, 90, 481–487.CrossRefGoogle Scholar
Ertl, A., Hughes, J.M., Prowatke, S., Ludwig, T., Brandstatter, F., Korner, W. and Dyar, M.D. (2007) Tetrahedrally coordinated boron in Li-bearing olenite from “Mushroom” tourmaline from Momeik, Myanmar. The Canadian Mineralogist, 45, 891–899.CrossRefGoogle Scholar
Francis, C.A., Dyar, M.D., Williams, M.L. and Hughes, J.M. (1999) The occurrence and crystal structure of foitite from a tungsten-bearing vein at Copper Mountain, Taos County, New Mexico. The Canadian Mineralogist, 37, 1431–1438.Google Scholar
Grice, J.D. and Ercit, T.S. (1993) Ordering of Fe and Mg in the tourmaline crystal structure: the correct formula. Neues Jahrbuch für Mineralogie Abhandlungen, 165, 245–266.Google Scholar
Grice, J.D., Ercit, T.S. and Hawthorne, F.C. (1993) Povondraite, a redefinition of the tourmaline ferridravite. American Mineralogist, 78, 433–436.Google Scholar
Hawthorne, F.C. (1996) Structural mechanisms for lightelement variations in tourmaline. The Canadian Mineralogist, 34, 123–132.Google Scholar
Hawthorne, F.C. (2002) Bond-valence constraints on the chemical composition of tourmaline. The Canadian Mineralogist, 40, 789–798.CrossRefGoogle Scholar
Hawthorne, F.C. and Henry, D.J. (1999) Classification of the minerals of the tourmaline group. European Journal of Mineralogy, 11, 201–215.CrossRefGoogle Scholar
Hawthorne, F.C., Macdonald, D.J. and Burns, P.C. (1993) Reassignment of cation site occupancies in tourmaline: Al-Mg disorder in the crystal structure of dravite. American Mineralogist, 78, 265–270.Google Scholar
Hawthorne, F.C., Ungaretti, L. and Oberti, R. (1995) Site populations in minerals: terminology and presentation of results of crystal-structure refinement. The Canadian Mineralogist, 33, 907–911.Google Scholar
Hawthorne, F.C., Burns, P.C. and Grice, J.D. (1996) The crystal chemistry of boron. Pp. 41–115 in: Boron: Mineralogy, Petrology and Geochemistry (Grew, E.S. and Anovitz, L.M., editors). Reviews in Mineralogy, 33, Mineralogical Society of America, Washington, D.C. CrossRefGoogle Scholar
Henry, D.J. and Dutrow, B.L. (1992) Tourmaline in lowgrade clastic sedimentary rocks: an example of the petrogenetic potential of tourmaline. Contributions to Mineralogy and Petrology, 112, 203–218.CrossRefGoogle Scholar
Henry, D.J. and Dutrow, B.L. (1996) Metamorphic tourmaline and its petrogenetic applications. Pp. 503–557 in: Boron: Mineralogy, Petrology and Geochemistry (Grew, E.S. and Anovitz, L.M., editors). Reviews in Mineralogy, 33, Mineralogical Society of America, Washington, D.C. CrossRefGoogle Scholar
Henry, D.J. and Guidotti, C.V. (1985) Tourmaline as a petrogenetic indicator mineral: an example from the staurolite-grade metapelites of NW Maine. American Mineralogist, 70, 1–15.Google Scholar
Hla Kyi, U., Themelis, T. and Kyaw Thu, U. (2005) The pegmatitic deposits of Molo (Momeik) and Sakan- Gya (Mogok). Australian Gemologist, 22, 303–309.Google Scholar
Hughes, J.M., Ertl, A., Dyar, M.D., Grew, E.S., Shearer, C.K., Yates, M.G. and Guidotti, C.V. (2000) Tetrahedrally coordinated boron in a tourmaline: boron-rich olenite from Stoffhütte, Koralpe, Austria. The Canadian Mineralogist, 38, 861–868.CrossRefGoogle Scholar
Hughes, J.M., Ertl, A., Dyar, M.D., Grew, E.S., Wiedenbeck, M. and Brandstätter, F. (2004) Structural and chemical response to varying [4]B content in zoned Fe-bearing olenite from Koralpe, Austria. American Mineralogist, 89, 447–454.CrossRefGoogle Scholar
Kroeker, S. and Stebbins, J.F. (2001) Three-Coordinated Boron-11 Chemical Shifts in Borates. Inorganic Chemistry, 40, 6239–6246.CrossRefGoogle ScholarPubMed
Lussier, A. and Hawthorne, F.C. (2011) Oscillatory zoned liddicoatite from central Madagascar. II. Compositional variation and substitution mechanisms. The Canadian Mineralogist, 49, 89–104.CrossRefGoogle Scholar
Lussier, A.J., Aguiar, P.M., Michaelis, V.K., Kroeker, S., Herwig, S., Abdu, Y. and Hawthorne, F.C., (2008a) Mushroom elbaite from the Kat Chay mine, Momeik, near Mogok, Myanmar: I. Crystal chemistry by SREF, EMPA, MAS NMR and Mössbauer spectroscopy. Mineralogical Magazine, 72, 747–761.CrossRefGoogle Scholar
Lussier, A.J., Hawthorne, F.C., Herwig, S., Abdu, Y., Aguiar, P.M., Michaelis, V.K. and Kroeker, S. (2008b) Mushroom elbaite from the Kat Chay mine, Momeik, nearMogok, Myanmar: II. Zoning and crystal growth. Mineralogical Magazine, 72, 999–1010.CrossRefGoogle Scholar
Lussier, A.J., Aguiar, P., Michaelis, V., Kroeker, S. and Hawthorne, F.C. (2009) The occurrence of tetrahedrally coordinated Al and B in tourmaline: An 11B and 27Al MAS NMR study. American Mineralogist, 94, 785–792.CrossRefGoogle Scholar
Lussier, A., Abdu, Y., Hawthorne, F.C., Michaelis, V.K., Aguiar, P.M. and Kroeker, S. (2011) Oscillatory zoned liddicoatite from central Madagascar. I. Crystal chemistry and structure by SREF and 11B and 27Al MAS NMR spectroscopy. The Canadian Mineralogist, 49, 63–88.CrossRefGoogle Scholar
Macdonald, D.J. and Hawthorne, F.C. (1995) The crystal chemistry of Si-Al substitution in tourmaline. The Canadian Mineralogist, 33, 849–858.Google Scholar
Macdonald, D.J., Hawthorne, F.C. and Grice, J.D. (1993) Foitite, ⇌Fe2+ 2 (Al,Fe3+)]Al6Si6O18 (BO3)3(OH)4, a new alkali deficient tourmaline: description and crystal structure. American Mineralogist, 78, 1299–1303.Google Scholar
Marler, B. and Ertl, A. (2002) Nuclear magnetic resonance and infrared spectroscopic study of excess-boron olenite from Koralpe, Styria, Austria. American Mineralogist, 87, 364–367.CrossRefGoogle Scholar
Marschall, H.R., Ertl, A., Hughes, J.M. and McCammon, C. (2004) Metamorphic Na- and OH rich disordered dravite with tetrahedral boron associated with omphacite, from Syros, Greece: chemistry and structure. European Journal of Mineralogy, 16, 817–823.CrossRefGoogle Scholar
Michaelis, V.K., Aguiar, P.M. and Kroeker, S. (2007) Probing alkali coordination environments in alkali borate glasses by multinuclear magnetic resonance. Journal of Non-Crystalline Solids, 353, 2582–2590.CrossRefGoogle Scholar
Neiva, A.M.R., Manuela, M., Silva, V.G. and Gomes, M.E. (2007) Crystal chemistry of tourmaline from Variscan granites, associated tin-tungsten- and gold deposits, and associated metamorphic and metasomatic rocks from northern Portugal. Neues Jahrbuch für Mineralogie Abhandlungen, 184, 45–76.CrossRefGoogle Scholar
Novák, M. and Povondra, P. (1995) Elbaite pegmatites in the Moldanubicum: a new subtype of the rare-element class. Mineralogy and Petrology, 55, 159–176.CrossRefGoogle Scholar
Novák, M., Selway, J., Černý, P., Hawthorne, F.C. and Ottolini, L. (1999) Tourmaline of the elbaite-dravite series from an elbaite-subtype pegmatite at Bliñná, southern Bohemia, Czech Republic. European Journal of Mineralogy, 11, 557–568.CrossRefGoogle Scholar
Pouchou, J.L. and Pichoir, F. (1985) ‘PAP’ φ(ρZ) procedure for improved quantitative microanalysis. Pp. 104–106 in: Microbeam Analysis (Armstrong, J.T., editor). San Francisco Press, San Francisco, California, USA.Google Scholar
Povondra, P. and Novák, M. (1986) Tourmalines in metamorphosed carbonate rocks from western Moravia, Czechoslovakia. Neues Jahrbuch für Mineralogie Monatshefte, 1986, 273–282.Google Scholar
Schreyer, W., Wodara, U., Marler, B., Van Aken, P.A., Seifert, F. and Robert, J.-L. (2002) Synthetic tourmaline (olenite) with excess boron replacing silicon in the tetrahedral site: I. Synthesis conditions, chemical and spectroscopic evidence. European Journal of Mineralogy, 12, 529–541.CrossRefGoogle Scholar
Selway, J., Černý, P. and Hawthorne, F.C. (1998) Feruvite from lepidolite pegmatites at Red Cross Lake, Manitoba. The Canadian Mineralogist, 36, 433–439.Google Scholar
Selway, J.B., Novák, M., Černý, P. and Hawthorne, F.C. (1999) Compositional evolution of tourmaline in lepidolite-subtype pegmatites. European Journal of Mineralogy, 11, 569–584.CrossRefGoogle Scholar
Selway, J.B., Novák, M., Černý, P. and Hawthorne, F.C. (2000a) The Tanco pegmatite at Bernic Lake, Manitoba. XIII. Exocontact tourmaline. The Canadian Mineralogist, 38, 869–976.CrossRefGoogle Scholar
Selway, J.B., Černý, P., Hawthorne, F.C. and Novák, M. (2000b) The Tanco pegmatite at Bernic Lake, Manitoba. XIV. Internal tourmaline. The Canadian Mineralogist, 38, 877–891.CrossRefGoogle Scholar
Selway, J.B., Smeds, S-A., Černý, P. and Hawthorne, F.C. (2002) Compositional evolution of tourmaline in the petalite-subtype Nyköpingsgruvan pegmatites, Utö, Stockholm Archipelago, Sweden. GFF, 124, 93–102.CrossRefGoogle Scholar
Sheldrick, G.M. (1998) SADABS User Guide, University of Göttingen, Germany.Google Scholar
Skibsted, J., Nielsen, N.C., Bildsøe, H. and Jakobsen, H.J. (1991) Satellite transitions in MAS NMR spectra of quadrupolar nuclei. Journal of Magnetic Resonance, 95, 88–117.Google Scholar
Tagg, S.L., Cho, H., Dyar, M.D. and Grew, E.S. (1999) Tetrahedral boron in naturally occurring tourmaline. American Mineralogist, 84, 1451–1455.CrossRefGoogle Scholar
Taylor, M.C., Cooper, M.A. and Hawthorne, F.C. (1995) Local charge-compensation in hydroxy-deficient uvite. The Canadian Mineralogist, 33, 1215–1221.Google Scholar
Themelis, T. (2007) Gems and Mines of Mogok: The Forbidden Land. A & T Press, Bangkok, Thailand.Google Scholar
Zaw, K. (1998) Geological evolution of selected granitic pegmatites in Myanmar (Burma): constraints from regional setting, lithology, and fluid-inclusion studies. International Geology Review, 40, 647–662.CrossRefGoogle Scholar