Abstract
The NMR spectra of 27Al and 23Na and the EPR spectra of Fe3+ and Mn2+ have been studied in a range of plagioclase feldspars, of intermediate composition. Many of these crystals have previously been investigated by TEM methods (McLaren and Marshall, 1974). The broad, central 27Al signals observed in labradorites have been interpreted in terms of an overall order/disorder of the Al/Si distribution. Spin Hamiltonian parameters have been determined for the Fe3+ spectra observed in labradorites and bytownites; these spectra were similar and yielded evidence of disordering of the Al/Si distribution. The severe limitations imposed by the variety of sites, the complex microstructures and the disordering, limit the structural information available from the resonance methods.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Asaa, R.: Powder Line Shapes in the Electron Paramagnetic Resonance Spectra of High-Spin Ferric Complexes. J. Chem. Phys. 52, 3919–3930 (1970)
Brinkmann, D., Ghose, S., Laves, F.: Nuclear magnetic resonance of 23Na, 27Al and 29Si and cation disorder in nepheline. Z. Krist. 135, 208–218 (1972)
Brinkmann, D., Staehli, J.L.: Magnetische Kernresonanz von 27Al im Anorthit, CaAl2Si2O8. Helv. Phys. Acta 41, 274–281 (1986a)
Brinkmann, D., Staehli, J.L.: 27Al-Kernresonanzmessungen von Anorthit bei höheren Temperaturen. Helv. Phys. Acta 41, 424 (1968b)
Brun, E., Hartmann, P., Staub, H.H., Hafner, S., Laves, F.: Magnetische Kernresonanz zur Beobachtung des Al, Si-Ordnungs/Unordnungsgrades in einigen Feldspäten. Z. Krist. 113, 65–76 (1960)
Cliff, G., Champness, P.E., Nissen, H.U., Lorimer, G.W.: Analytical Electron Microscopy of Exsolution Lamellae in Plagioclase Feldspars. In: Electron Microscopy in Mineralogy, Wenk, H.R. (ed.). Berlin Heidelberg New York: Springer 1976, pp. 258–265
Fleet, S.G., Chandrasekhar, S., Megaw, H.D.: The Structure of Bytownite (‘Body-Centred Anorthite’). Acta Cryst. 21, 782–801 (1966)
Gaite, J.M., Michoulier, J.: Application de la résonance paramagnétique électronique de l'ion Fe3+ à l'étude de la structure des feldspaths. Bull. Soc. Franc. Minéral. Crist. 93, 341–356 (1970)
Ghose, S., Tsang, T.: Structural Dependence of Quadrupole Coupling Constant e2qQ/h for 27Al and Crystal Field Parameter D for Fe3+ in Aluminosilicates. Am. Mineral. 58, 748–755 (1973)
Hafner, S., Hartmann, P.: Elektrische Felgradienten und Sauerstoff-Polarisierbarkeit in Alkali-Feldspäten (NaAlSi3O8 und KAlSi3O8). Helv. Phys. Acta 37, 348–360 (1964)
Hafner, S., Hartmann, P., Laves, F.: Magnetische Kernresonanz von 27Al in Adular. Zur Deutung der Akularstruktur. Schweiz. Mineral. Petrog. Mitt. 42, 277–294 (1962)
Hafner, S.S., Niebuhr, H.H., Zeira, S.: Dreiwertiges Eisen in einem Anorthit-Kristall vom Mond. Naturwiss. 60, 473 (1973)
Kolopus, J.L., Kline, D., Chatelain, A., Weeks, R.A.: Magnetic resonance properties of lunar samples: Mostly Apollo 12. Proc. Second Lunar Sci. Conf. 3, 2501–2514 (1971)
Lesnov, F.P., Shcherbakova, M.Ya., Istomin, V.Ye. Fe(III) ESR Spectra and the Types of Plagioclase from Gabbroids. Geochem. International 10, Abstr. GI73-2-8 (1973) Translated from Geokhimiya 2, 293–297 (1973)
Marfunin, A.S., Bershov, L.V., Meilman, M.L., Michoulier, J.: Paramagnetic Resonance of Fe3+ in some Feldspars. Schweiz. Mineral. Petrog. Mitt. 47, 13–20 (1967)
McLaren, A.C., Marshall, D.B.: Transmission Electron Microscope Study of the Domain Structures Associated with the b-, c-, d-, e-, and f- Reflections in Plagioclase Feldspars. Contrib. Mineral. Petrol. 44, 237–249 (1974)
Michoulier, J., Gaite, J.M.: Site Assignment of Fe3+ in Low Symmetry Crystals. Application to NaAlSi3O8. J. Chem. Phys. 56, 5205–5213 (1972)
O'Reilly, D.E.: Quadrupolar Broadened Nuclear Magnetic Resonance of Polycrystalline Solids. J. Chem. Phys. 28, 1262–1264 (1958)
Phillips, M.W., Colville, A.A., Ribbe, P.H.: The crystal structure of two oligoclases: A comparison with low and high albite. Z. Krist. 133, 43–65 (1971)
Scala, C.M.: Magnetic resonance studies of silicate minerals. Ph.D. thesis, Monash University 1976
Shcherbakova, M.Ya., Istomin, V.E.: Calculation of EPR Spectra of Fe3+ with High Zero-Field Splitting in Polycrystalline Materials. Phys. Status. Solidi. (B) 67, 461–469 (1975)
Smith, J.V.: Feldspar Minerals. Vol. 1 Crystal Structure and Physical Properties. Berlin Heidelberg New York: Springer 1974
Staehli, J.L., Brinkmann, D.: A nuclear magnetic resonance study of the phase transition in anorthite. Z. Krist. 140, 360–373 (1974a)
Staehli, J.L., Brinkmann, D.: Assignment and structural dependence of electric field gradients in anorthite and simple field gradient calculations in some aluminosilicates. Z. Krist. 140, 374–392 (1974b)
Wainwright, J.E.: A refined structure for bytownite. Progr. Eighth Inter. Congr. Crystallography, Abstr. XII-48 (1969). As reported and referenced by Smith (1974)
Wainwright, J.E., Starkey, J.: A refinement of the structure of anorthite. Z. Krist. 133, 75–84 (1971)
Weeks, R.A.: Paramagnetic Resonance Spectra of Ti3+, Fe3+ and Mn2+ in Lunar Plagioclases J. Geophys. Res. 78, 2393–2401 (1973)
Ya, Y.H.: g=4.3 Isotropic EPR Line in Tourmaline. J. Chem. Phys. 57, 3020–3022 (1972)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Scala, C.M., Hutton, D.R. & McLaren, A.C. NMR and EPR studies of the chemically intermediate plagioclase feldspars. Phys. Chem. Minerals 3, 33–44 (1978). https://doi.org/10.1007/BF00357445
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00357445