Silica veins in Gaj-Lazine locality (Central Serbia) as gemstone

Gemstone occurrence Gaj-Lazine is located in central Serbia, 3.5 km SE of Stragari. Prevailing gemstone type is opaque chalcedony-jasper and colourless chalcedony. Subordinate crystalline quartz and carbonate minerals are also present. They all appear as single veins and, more often, intricate stock works, filling up fractures in serpentinite of the Vardar zone ophiolitic sequence. Genetic processes of this occurrence are connected to the Neogene calc-alkaline magmatic activity of the Vardar zone and hydrothermal activity triggered by it. Economic significance of this gemstone deposit is high for jasper and minor for other present gemstone types, due to their minor occurrences. (Author)