I have deafeated the elite four and I want to face mewtwo.But I read that I need to give some rare gems to celio first!When I speak to celio he tells me that he wants some kind of gem for his machine to make trades.He also says that the gems are located somewhere in one island.Where exactly can I find these gems?
Plz Help!

Go to Mt ember, and instead of going where Moltres is, go the other way, Two Rockets will be there, you should be able to figer the rest out

1.Well,I reached seven island and in sevault canyon I found a cave called "Tanoby Key"I solved the puzzle with the boulders and an earthquake happened which opened a door somewhere.Where is that door?
2.In tanoby ruins is there a special secret with unknowns?
3.In "two island" there is a woman in the north up the waterfall who tells you that she has the best move of a pokemon kind.When i went there the first tima she taught to my blastoise the "Hydro cannon"move.But when i visit her again she tells me that she has completed another special move of its kind but I don't know which pokemon give her.I have tried it with all my pokemon!

Can you help me with those questions?