I wish to buy an original


I wish to buy an original true blue sapphire of around 3 – 3.5 carat for astrological purpose…but I am afraid that I may not be able to judge a true and a fake treated one… Most of the stones here are from Ceylone, Sri Lanka. Can you please guide me somewhere from where I can purchase a true original one. I am living in Dubai. The following website of a seller in Dubai claims that he has some certified gemstones by International Gemological Institute, I am not sure if you have an idea about it and its authenticity? Kindly visit http://www.ceylonmastergems.com and then to certified gemstones to see them. I would be grateful if you would give me a rough idea of how much it should cost? Thanx