FTIR spectroscopy in the OH-stretching region of monoclinic epidotes from Praborna (St. Marcel, Aosta valley, Italy)
Della Ventura, Giancarlo; Mottana, Annibale; Parodi, Gian Carlo; Griffin, William L.
European Journal of Mineralogy Volume 8 Number 4 (1996), p. 655 - 666
published: Jul 29, 1996
manuscript accepted: Feb 12, 1996
manuscript received: Aug 28, 1995
ArtNo. ESP147050804001, Price: 29.00 €
Abstract This paper deals with a crystal-chemical, infrared spectroscopic study of monoclinic epidotes from Praborna (St. Marcel, Val d' Aosta, Italy). The studied samples range in composition from clinozoisite (Czo) to Sr-rich piemontite (Pm). In the OH-stretching region, (Al,Fe3+)-clinozoisites show a single broad band centred in the range 3345-3380cm-1 which is assigned to the [M2]Al-O10 → H...O4-[M1'3](Al,Fe3+) configuration. The spectra of Sr-rich piemontites show a well-resolvable doublet at almost constant wavenumbers (3417/3454 cm-1) which can be explained by two simultaneous effects: (i) the entry of Mn3+ in the non-OH-coordinated M3 octahedra and, (ii) the entry of Sr substituting for Ca in A2.