Abstract
This work is part of a project focused on the Somma–Vesuvius volcano and aimed at identifying Cu minerals related to mineralizing processes associated with magmatic activity in an active magmatic-hydrothermal system. A mineralogical survey was carried out on a set of samples represented by sublimates and fumarolic products from the collection of the Mineralogical Museum of the University of Naples Federico II (Italy). These samples are mainly related to most recent eruptive episodes of Vesuvius activity, from 1631 onward. Copper-bearing minerals were characterized, as well as associated minerals, by X-ray diffraction (XRD) scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). An investigation on the structural complexity of Cu-mineral assemblages with different temperature formations was also carried out using the TOPOS software package. The main copper phases are sulfates, followed by vanadates, hydroxyhalides, oxides, carbonates, silicates and finally, phosphates. New mineral occurrences for Vesuvius, both Cu-bearing and Cu-free, are described. Nevertheless, the fumarolic/alteration minerals at Vesuvius cannot be considered of economic relevance as a copper reservoir, this type of mineralizations are significant for copper crystal chemistry and for the knowledge of the mineralogical variants. The obtained datasets can be of interest for the knowledge of volcanic byproducts of copper ore deposits (i.e., porphyry copper systems) and of (base) metal segregation processes.
Highlights
Copper is a base metal and the 26th most abundant element in the Earth’s crust, with concentrations ranging from 26 to 28 ppm in the continental crust [1] and less than 44 ppm in the lower oceanic crust [2].As a transition metal, Cu is moderately siderophile and strongly chalcophile, with approximately two thirds of terrestrial Cu thought to be stored in the core [3]
In nature, copper occurs in a great variety of minerals; according to the mindat.org database [5], it is essentially contained in 562 valid mineral species, in decreasing order of abundance, hosted in sulfides–sulfosalts, phosphates–arseniates–vanadates, sulfates, oxides, halides, silicates, carbonates, borates and native elements
Of the Mineralogical Museum of the Naples University (Italy), where copper minerals typically occur as encrustations and/or tiny patinas, coatings and/or void filling associated with the historical activity of Vesuvius
Summary
Copper is a base metal and the 26th most abundant element in the Earth’s crust, with concentrations ranging from 26 to 28 ppm in the continental crust [1] and less than 44 ppm in the lower oceanic crust [2].As a transition metal, Cu is moderately siderophile and strongly chalcophile, with approximately two thirds of terrestrial Cu thought to be stored in the core [3]. In the silicate Earth, it behaves as a chalcophile element and usually forms stable sulfides, among which chalcopyrite (CuFeS2 ) is the most common Cu-bearing mineral; copper is a common constituent, together with silver, in natural sulfosalts [4]. In nature, copper occurs in a great variety of minerals; according to the mindat.org database [5], it is essentially contained in 562 valid mineral species, in decreasing order of abundance, hosted in sulfides–sulfosalts, phosphates–arseniates–vanadates, sulfates, oxides, halides, silicates, carbonates, borates and native elements. Copper is an economically important base metal It forms large and rich ore deposits with exceptional mineral diversity; major ore sulfide minerals include, in addition to the aforementioned chalcopyrite CuFeS2 (35% Cu), bornite Cu5 FeS4 (63% Cu), covellite CuS (66% Cu) and chalcocite Cu2 S (80% Cu). The top Cu producers are Chile, USA, Indonesia and Peru [7,9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
