A Raman and infrared spectroscopic study of Ca2+ dominant members of the mixite group from the Czech Republic



The minerals of the mixite group—zálesíite CaCu6[(AsO4)2(AsO3OH)(OH)6]·3H2O from abandoned uranium deposit Zálesí, Czech Republic and calciopetersite CaCu6[(PO4)2(PO3OH)(OH)6]·3H2O from a quarry near Domašov na Bystřicí, northern Moravia, Czech Republic—were studied by Raman and infrared spectroscopy. The observed bands were assigned to the stretching and bending vibrations of (AsO4)3− and (AsO3OH)2− ions in zálesíite, and (PO4)3− and (PO3OH)2− in calciopetersite, and to molecular water, hydroxyl ions, and Cu-(O,OH) units in both minerals. O[BOND]H···O hydrogen-bond lengths in zálesíite and calciopetersite structures were calculated with Libowitzky's empirical relation. Copyright © 2010 John Wiley & Sons, Ltd.