Anglesite, Cerussite, Gypsum, Langite, Malachite, and Posnjakite: New Occurrences in the Calabria Region (Southern Italy)

Abstract

This study undertook the mineralogical and chemical analysis of anglesite (PbSO4), cerussite (PbCO3), gypsum (CaSO4∙2H2O), langite (Cu4(SO4)(OH)6∙2H2O), malachite (Cu2CO3(OH)2), and posnjakite (Cu4(SO4)(OH)6·H2O) detected for the first time in the abandoned Mastricarro Barite Mine (Catanzaro, Calabria, southern Italy). Geological conditions make this one of the few well-preserved, partly accessible mines in the Calabria region. Numerous mineralogical species, some beautifully crystallized, have been discovered among the alteration products of the sulfides present within the barite veins. The newly identified crystals occur as secondary minerals in the oxidized portions of deposits originally containing lead and copper sulfides; they are widely distributed and are almost always detected as microcrystals. The anglesite, cerussite, gypsum, langite, malachite, and posnjakite crystals were identified and characterized using optical microscopy (OM), micro-Raman spectroscopy (µR), and scanning electron microscopy, combined with energy dispersive spectrometry (SEM/EDS). The new mineral occurrences can be useful for scientific and didactic purposes; further, for langite, malachite, and posnjakite crystals, new Raman bands, which have not been mentioned before in the literature, were identified.