Chalcedony. A semi-important gemstone named once the nearby city of Chalcedon, and it is marketed in most of Istanbul's large number of jewellery outlets. Presently, most metro stations do not have a staffed ticket booth, so you will have to receive your Istanbulkart in the yellow ticket machines. By tram[edit] https://andyvursp.thenerdsblog.com/42869068/facts-about-istanbul-work-revealed