Abstract
The electronic absorption spectra of Fe2+ in non-chromium beryls are examined. Fe2+ in the Al-rich six-coordinate site produces absorption bands at about 820 nm and 970 nm polarizedE‖c. Fe2+ in the channel produces bands at 820 nm (⊥c) and 2100 nm (‖c). Some blue beryls which are more intensely colored than most aquamarines, have an absorption band at ∼700 nm (‖c) which is suggested to arise from an Fe2+/Fe3+ intervalence interaction. Fe2+ in both the six-coordinate site and the channel is identified in the Mössbauer spectra. The Mössbauer spectra of deep blue beryls are unusual and have not been satisfactorily explained. Color changes which accompany heating and irradiation are strongly influenced by the channel iron.
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Farrell, E.F., Newnham, R.E.: Electronic and vibrational absorption spectra in cordierite. Am. Mineral.52, 380–388 (1967)
Faye, G.H.: Relationship between crystal-field splitting parameter, “δVI”, and Mhost-O bond distances as an aid in the interpretation of absorption spectra of Fe2+-bearing materials. Can. Mineral.11, 273–487 (1972)
Faye, G.H., Nickel, E.H.: On the origin of color and pleochroism of kyanite. Can. Mineral.10, 35–46 (1969)
Gibbs, G.V.: The polymorphism of cordierite I: the crystal structure of low cordierite. Am. Mineral.51, 1068–1087 (1966)
Gibbs, G.V., Breck, D.W., Meagher, E.P.: Structural refinement of hydrous and anhydrous synthetic beryl, Al2(Be3Si6)O18 and emerald, Al1.9Cr0.1(Be3Si6)O18. Lithos1, 275–285 (1968)
Goldman, D.S., Rossman, G.R.: The identification of Fe2+ in the M(4) site of calcic amphiboles. Am. Mineral.62, 205–216 (1977)
Goldman, D.S., Rossman, G.R., Dollase, W.A.: Channel constituents in cordierite. Am. Mineral.62, (1977)
Loeffler, B.M., Burns, R.G.: Shedding light on the color of gems and minerals. Am. Sci.,64, 636–647 (1976)
Parkin, K.M., Loeffler, B.M., Burns, R.G.: Mössbauer spectra of kyanite, aquamarine, and cordierite showing intervalence charge transfer. Phys. Chem. Minerals.1, 301–311 (1977)
Pfannes, H.D., Gonser, U.: Goldanskii-Karyagin effect versus preferred orientations (texture), Appl. Phys.,1, 93–102 (1973)
Price, D.C., Vance, E.R., Smith, G., Edgar, A., Dickson, B.L.: Mössbauer effect studies of beryl. J. Phys. (accepted for publication) (1978)
Samoilovich, M.I., Isinober, L.I., Dunin-Barkovskii, R.L.: Nature of the coloring in iron-containing beryl. Kristallografiya,16, 186–189 (1971) [Transl. Soviet Physics — Crystallography16, 147–150 (1971)]
Shannon, R.D., Prewitt, C.T.: Effective ionic radii in oxides and fluorides. Acta Cryst.B25, 925–946 (1969)
Sinkankas, J.: Gemstone and Mineral Data Book. New York: Winchester Press, p. 114. (1972)
Wood, D.L., Nassau, K.: Infrared spectra of foreign molecules in beryl. J. Chem. Phys.47, 2220–2228 (1967)
Wood, D.L., Nassau, K.: The characterization of beryl and emerald by visible and infrared absorption spectroscopy. Am. Mineral.53, 777–800 (1968)
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Don Goldman, S., Rossman, G.R. & Parkin, K.M. Channel constituents in beryl. Phys Chem Minerals 3, 225–235 (1978). https://doi.org/10.1007/BF00633572
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DOI: https://doi.org/10.1007/BF00633572