Was taken there on a tour recommended and arranged by hotel. Sales person in a suit showed us some sultanite and we were very intrigued, bought some items and received certificate. Subsequient research revealed that it was not sultanate and rather treated glass. Returned items next day and was refunded after a battle. Sultanite is not avaliable inside Turkey, do your research and dont be fooled by a certificate printed on site. After we received the refund we found the same items in Goreme for 1/5 the price