Journal of

GEOsciences

  (Formerly Journal of the Czech Geological Society)

Original Paper

Ivan Vavřín, Jiří Frýda

Cu-Ag-V mineralization in melaphyre from Studenec near Jilemnice (foothills of the Giant Mts., Czech Republic)

Journal of the Czech Geological Society, volume 41 (1996), issue 1-2, 33 - 39

Copper mineralization found in the melaphyre is represented mostly by native copper accompanied by cuprite, chrysocolla and malachite. Native silver, mercurian silver (kongsbergite) together with vanadium minerals such as vegisnieite and Ag-V silicate are rather accessoric. The cooper mineralization is solely confined to altered parts of the melaphyre which are conspicuously depleted in Fe, Mg, Ca and slighty enhanced in K and Na. The native copper contains only negligible admixture of Hg. silver is characteristic of an admixture of Hg and Cu. The oxidation of native copper led to the origin of cuprite whereas released mercury entered the structure of native silver to form mecurian silver. Various types of cuprite were found to be relatively pure without any admixture of As and V. A silicate containing copper and enhanced concetrations of vanadium up to 3 % V₂0₅ appears to be the primary source of vanadium to form vesignieite. The succession of minerals corresponds to an increasing fugacity of oxygen and low fugacity of sulfur.