Carpathian Journal of Earth and Environmental Sciences

The study area is located in the western part of the Southern Carpathians, Romania. From a stratigraphical, morphological and geological point of view, it pertains to the Petroşani Basin, which is almost entirely crossed by Jiul de Vest River. Several occurrences of sulfates were identified in the upper basin of the river. The samples were collected from two perimeters, namely „Scocul Jiului” (P1) and „Tusu brook” (P2), located on the right tributary of the Jiu River. The sulfates discovered are water-bearing, pertaining to halotrichite - pickeringite isomorphic series, halotrichite and pickeringite being the main minerals observed, along with alunogen and gypsum. The sulfate minerals accompany pyrite micro-veins crossing metamorphic rocks (gneisses). The minerals were investigated using X-ray powder diffraction (XRD), infrared absorption spectrometry, micro-Raman spectrometry, scanning electron microscopy (SEM), combined with energy dispersion spectroscopy (SEM–EDS) and optical study. The chemical and textural complexity suggests the existence of minerals in the halotrichite - pickeringite isomorphic series, mixed in different proportions; alunogen and gypsum provided Raman and infrared spectra very close to those of synthetic samples in literature.