Chalcedony. A semi-treasured gemstone named following the nearby city of Chalcedon, and is particularly bought in many of Istanbul's large number of jewellery outlets. Currently, most metro stations do not need a staffed ticket booth, so you will need to get hold of your Istanbulkart within the yellow ticket equipment. https://traviskvfpa.thezenweb.com/the-basic-principles-of-istanbul-wordpress-74952892