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Chromian mica from Sierra Nevada, Spain

Published online by Cambridge University Press:  05 July 2018

J. D. Martín-Rabios
Affiliation:
Department of Crystallography and Mineralogy, University of Granada, Spain
M. Rodriguez-Gallego
Affiliation:
Department of Crystallography and Mineralogy, University of Granada, Spain

Synopsis

Emerald green chromian 2M1 mica occurs in metamorphosed and metasomatized limestones, related to serpentinic rocks from Sierra Nevada, Spain. Chemical analysis gave: SiO2 44.51, Al2O3 27.60, TiO2 0.17, Cr2O3 3.35, Fe2O3 1.76, FeO 0.07, MnO 0.00, MgO 8.59, Li2O 0.03, Rb2O 0.01, BaO 0.01, CaO 1.71, Na2O 0.40, K2O 7.86, H2O 4.21 = 100.28. Optic properties are: pleochroism X blue, Y green, Z bluish green; refractive indices: α=1.562, β=1.611, γ=1.616 (yellow light); inclined dispersion, r > v. Orientation: second order mica. Refined parameters are a = 5.2116(6), b = 9.045(2), c = 19.97(2)Å, β = 95.7(3)°. The structure is discussed and an order in the octahedral M(1) sites is observed, but no ordering in the tetrahedral T(1) and T(2) cations is detected. The mica described is a mariposite with anoma-lously high contents of Ca and Mg.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1982

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References

Bailey, S.W. (1975). Cation orderlng and Pseudosymmetry in layer silicates. Am.Mineral, 60, 175187.Google Scholar
Busing, W.R., Martin, K.O. and Levy, H.A. (1962). ORFLS, a Fortran crystallographic least-squares refinment program U. S. Natl. Tech. Inf. Serv., ORNL-TM-305.Google Scholar
Chanq-pao-Kwei, and Lin-KUo-Cheng, (1974). Chrome phlogopite -a new subspecies of phlogopite (abstr.). Geochim., 1. 7174.Google Scholar
Chatergee, N.D. (1966). Chromlan phengite in an ankerite marble from the suse Valley Western Italian Alps. Neues Juhrb. Mineral Mh., 103110.Google Scholar
Guven, N. (1971). The crystal structures of 2M1 phenglte and 2M1 muscovite. Z.Kristallogr, 234, 196212.Google Scholar
Hornstra, J. and Stubbe, B. (1972). Pw-1100 data proceossing program. Philips Research Labs, Eindhoven, Holland.Google Scholar
Ibers, J.A. and Hamilton, W.C. (EdS.) (1974). International Tables for X-Ray Crystallography, IV. 99-101. Kynoch Press, Birmingham.Google Scholar
Langmyhr, J.F. and Paus, F.E. (1968). The analysis of inorganic siliceous materials hy atomic absorption spectrophotometry and the hydrofluoric acid decomposition technique. Part II. The analygis of silica. Anal. Chim. Acta, 43, 506510.CrossRefGoogle Scholar
Langmyhr, J.F. and Paus, F.E. (1958). The analysis Df inorganic siliceous materials by atomic absorption spectrophotometry and the hydrofluoric acid decomposition technique. Part. I. The analysis of silicate rocks. Anal. Chim. Aota, 43, 397408.CrossRefGoogle Scholar
Linares, J. y Huertas, F. (1973). Normas para el anállsis químico de minerales y rocas. C.S.I.C. Granada; Spain.Google Scholar
Martín-Ramos, J.D. (1976). Lag micas de la Cordillera Bética. Geol.D. Thesis. Granada University, spain.Google Scholar
Martín-Ramos, J.D., Rodríguez Gallego, M. y Burgos, J. (1979). Sobre una mica crómica de Sierra Nevada. Soc. Esp. Mineral, 1, 93102.Google Scholar
Pérez del Villar, L. (1972). Estudio geológico del área comprendida entre las rambias del Raposo y del agua. Geol.L.Thesis. Granada University, Spain.Google Scholar
Puga, E., Diaz de Federlco, A. y Fontboté, J.M. (1974). Sohre la individuallzación y sistematización de las unidades profundas de la zona Bética. Estudios Geol., 30, 543548.Google Scholar
Radoslovich, E.W. (1962). The cell dimension and symmetry of layer lattice silicates. IV Interatomic forces. Am. Mineral., 48, 7699.Google Scholar

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