@ARTICLE{Başibüyük_Zeynel_Mineralogical,_2020,
 author={Başibüyük, Zeynel and Akbudak, Ilkay Kaydu and Gürbüz, Meltem},
 volume={vol. 36},
 number={No 1},
 journal={Gospodarka Surowcami Mineralnymi - Mineral Resources Management},
 pages={77-92},
 howpublished={online},
 year={2020},
 publisher={Komitet Zrównoważonej Gospodarki Surowcami Mineralnymi PAN},
 publisher={Instytut Gospodarki Surowcami Mineralnymi i Energią PAN},
 abstract={Ch-chalcedony is a green colored member of the quartz group of gem stones. The appearance of Ch-chalcedony is very similar to that of chrysoprase. Differently, Ch-chalsedonies have a chromium element instead of a nickel element as a trace element. Green quartz used in jewelery as a seal stone, in necklaces and rings and has been one of the most valuable quartz varieties throughout history, with its beautiful green color,more rare than other quartz varieties. The Ch-chalcedonies in the North Anatolian region is yellowish-white, brownish gray, light green to dark green in color ranging from several centimeters to one meter thick in veins and lenses in the Lower-Middle Eocene dolomitic limestones. Ch-chalcedonies are composed of fine-grained and occasionally fibrous needle-like quartz; in some examples, quartz is present together with cristobalite, tridimite and cuspidine minerals. According to geochemical investigations in Ch-chalcedonies, the main oxides that were determined are as follows: SiO2 was observed in the range of 95.86–97.81%, Fe2O3 was observed in the range of 0.61–0.91% and Cr2O3 was observed in the range of 0.125–0.168%. A trace element analysis of Ch-chalcedonies, shows their significant enrichments in: Ni, Mo, Cu, Mn, V, Cr and W, especially in the Cr (up to 705 ppm). The green color of the studied Cr-chalcedonies originates from the element chromium. Taking the possible reserves into account, the hardness, color, massive structures, mineralogical, petrographical and gemological features of Ch-chalcedonies in the region are evaluated together. It is determined that they are suitable for the production of jewelry and ornaments.},
 type={Article},
 title={Mineralogical, geochemical and gemological investigation of Artova Ch-chalcedonies, Tokat – Turkey},
 URL={http://ochroma.man.poznan.pl/Content/115816/PDF/basibuk-akbudak-gurbuz.pdf},
 doi={10.24425/gsm.2020.132551},
 keywords={Ch-chalcedony, gemstone, green quartz, gemology, Turkey},
}