Abstract
Arsenate and sulfate minerals are typical and abundant products of supergene alteration of primary sufidic ores, occurrying either in oxidation zones of ore deposits or in dumps and mill-tailing. These minerals play an important environmental role since they represent an important sink for metal elements. Aim of this project is to broaden and supply our knowledge about these minerals, namely with regard to their crystal structures, chemistry and about evolution of the alteration associations of these phases.