title: Spectral-structural characteristics of the extremely scarce silver arsenic sulfosalts, proustite, smithite, trechmannite and xanthoconite: μ-Raman spectroscopy evidence.
abstract: The spectral - structural features of the rare silver arsenic (Ag-As) sulfosalts, proustite, Ag3AsS3, and the extremely scarce smithite, AgAsS2, trechmannite, AgAsS2and xanthoconite, Ag3AsS3, were studied by the μ-Raman technique. Stretching - bending vibrations of the pyramidal isolated and interconnected AsS3groups were responsible for the Raman spectra of the studied sulfosalts. The symmetric and asymmetric stretching modes appear between 380 and 350cm-1, whereas those of bending (SAsS) vibrations between 335 and 280cm-1. The AsS longer bond lengths absolutely demonstrate the red shift (i.e. decrease in energy) from xanthoconite to trechmannite, smithite and proustite and the lowering in FWHM in comparable vibrational modes.
authors.affiliation: Geology Department, Faculty of Science, Suez University, Suez Governorate, El Salam City 43518, Egypt. Electronic address: sherif.abdalla@suezuniv.edu.eg.
authors.forename: S
authors.initials: S
authors.lastname: Kharbish
keywords: Proustite; Raman spectroscopy; Smithite; Trechmannite; Xanthoconite