Silica veins in gaj-lazine locality (Central Serbia) as gemstone

Abstract

Gemstone occurrence Gaj-Lazine is located in central Serbia, 3.5 km SE of Stragari. Prevailinggemstone type is opaque chalcedony–jasper and colourless chalcedony. Subordinate crystalline quartz and carbonateminerals are also present. They all appear as single veins and, more often, intricate stockworks, filling up fractures inserpentinite of the Vardar zone ophiolitic sequence. Genetic processes of this occurrence are connected to the Neogenecalc-alkaline magmatic activity of the Vardar zone and hydrothermal activity triggered by it. Economic significanceof this gemstone deposit is high for jasper and minor for other present gemstone types, due to their minor occurrences.