Morphological characteristics of chalcocite from mineral-geological complexes in Ukraine

Abstract

Background. Chalcocite-containing ores are among the richest high-quality copper ores, a significant part of the world's copper production falls on them. In Ukraine, chalcocite is a moderately common mineral. Information on the abundance, forms of occurrence and morphology of this mineral in geological formations of Ukraine has varying levels of detail of research. This work aims to systematize and analyze the currently existing data on chalcocite in Ukraine.
Methods. In this work, a systematic review of the literature devoted to the research of geology and mineralogy of mineralogical and geological complexes of Ukraine was used. Goniometric (double-circle goniometer GD-1), electron microscopy (electron microscope JSM-6700F (JEOL, Japan) equipped with an energy dispersive system for X-ray microanalysis JED-2300 (JEOL, Japan)) methods were used to study chalcocite from Volyn basalts.
Results. Information on the spread, forms of occurrence and morphology of chalcocite crystals in geological formations of Ukraine are summarized. The mineral is represented by numerous morphological forms and is found in almost all mineralogical provinces of Ukraine.
Conclusions. Chalcocite in the geological formations of Ukraine has quite a variety of forms, which are primarily due to the peculiarities of the genesis of the mineral: crystals of different morphological types, regular intergrowths (twins). Less often there are dendritic-like secretions, most often these are separate grains, xenomorphic, lamellar, spindle- and ribbon-like secretions, small lenses, veins. Chalcocite is often found in nodules and concretions, observed as finely diffused inclusions in cement or as cement itself. When replacing other minerals, it can form borders, looped structures, subgraphic growths, incomplete and complete pseudomorphoses. Chalcocite is also found as pseudomorphs of organic remains. According to the genesis in the mineralogical and geological complexes of Ukraine, there are two types of chalcocite: hypogenic and hypergenic. The latter is divided into primary (syngenetic), which was formed together with stratum sediments, and secondary (dia- and catagenetic), which replaced primary sulfides. The analyzed information from primary sources also demonstrates the facts of insufficient study of chalcocite. All this indicates the need for a more detailed study of this mineral, given its important role as a source of copper mining.