The Azul Jewel

There is an exotic island in the Southern Atlantic Ocean around the tip of Brazil. The people who inhabit the Island are ancient...more ancient than any ruins you'd ever find in messo-america. Every 1000 years they change. Their religion, the way they dress, their Architecture and their language it all changes. And the best part is they are immortal. And when the 1000 years are up and they change their memories are erased.
Sabria is a 16 year old girl who has lived a lucky life. Her parents are both rich Senators in South America. She has all of the new clothes and technology that any teenager could ever want, but she doesn't care about any of that. She just wants to go to the library and cuddle into a comfy corner and read a book. Preferably about ancient history.
When Sabria meets Anjé, a boy with a mysterious past, she can't help but feel like there's something she's missing. When she and Anjé go to the island that changes, she finds that not all is as it seems.