Abstract: The chalcedony formations observed in the village of Nebiköy and its surroundings in Tokat province arefound in Permian-Triassic metamorphic rocks as veins with a thickness a few mm to 10 cm. Chalcedony, which hascolor of light blue-blue tones, is generally banded and sometimes has a kidney-like structure.In thin sections made from chalcedony, fibrous acicular quartz minerals and microcrystalline quartz mineralswere determined in a banded structure. Iron oxide fillings were encountered in the secondary dolomite formationsand micro-fractured cracks that cut these minerals in places. Quartz and dolomite associations were detected inXRD analyzes of the chalcedony samples.The main oxides in the chalcedony sample taken from the study area were determined as 94.08% SiO2, 1.45%CaO, 1.06% MgO, 0.37% Al2O3 and 0.31% Fe2O3; In the host rock (metasandstone) sample, it was determined as 37.5% SiO2, 16% CaO, 8% MgO, 6% Al2O3 and 4% Fe2O3. In the chalcedony sample, enrichments were alsoobserved in trace elements of 140.4 ppm As, 36.97 ppm Co, 5.4 ppm Ni and 1.45 ppm Cu; while in the host rock,enrichments were observed in trace elements of 53.3 ppm V, 28.9 ppm Ni, 7.5 ppm Co, 4.8 ppm As, 4.6 ppm Cu, 2.4ppm Mo, 2 ppm Ga and 1.5 ppm Bi.Cabochon cutting studies were carried out from the chalcedony samples taken from the study area to be usedin jewelry. Considering the light-dark blue color tone, durability, massive structure and workability observed in anarea of approximately 1 km2, it was determined that the chalcedony in the region can be used as gemstones.