New Structural and Spectroscopic Data for Eosphorite

M. A. Hoyos, T. Calderon, I. Vergara and J. Garcia-Solé
Dept. Quimica-Agricola-Geologia y Geoquìmica Univ. Autònoma de Madrid, Cantoblanco, Spain
Dept. Fisica de Materiales, C-IV, Univ. Autònoma de Madrid, Cantoblanco, Spain

Abstract: X-ray diffraction refinement of the crystal structure of eosphorite has been carried out with reference to the orthorhombic space group Cmca. The structure is similar to that previously described by Hanson (1960), but the standard deviations are improved. Optical absorption and photoluminescence have also been studied for this mineral. Two sharp emission lines, denoted as R1 and R2, superimposed to a broad band (630–750 nm) have been related to the presence of Cr3+ ions. The excitation spectrum of these emissions confirms that the absorption (excitation) bands centred at 431 nm and 585 are related to with 4A24T1 and 4A24T2 spin allowed transitions of this ion.

Keywords: eosphorite • crystal structure • luminescence optical absorption

Mineralogical Magazine; June 1993 v. 57; no. 387; p. 329-336; DOI: 10.1180/minmag.1993.057.387.16
© 1993, The Mineralogical Society
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