Raman microscopy of the mixite mineral BiCu6(AsO4)3(OH)6·3H2O from the czech republic

Abstract

Raman microscopy of the mixite mineral BiCu6(AsO4)3(OH)6·3H2O from Jáchymov and from Smrkovec (both Czech Republic) has been used to study their molecular structure. The presence of (AsO4)3-, (AsO3OH)2-,(PO4)3- and (PO3OH)2- units, as well as molecular water and hydroxyl ions, was inferred. O-H· ··O hydrogen bond lengths were calculated from the Raman and infrared spectra using Libowitzky's empirical relation. Small differences in the Raman spectra between both samples were observed and attributed to compositional and hydrogen-bonding network differences. © 2009 John Wiley & Sons, Ltd.