where do i get the next crystal for cellio in Pokemon Leaf green? And what do I do with The Unown Pokemon?

Question

Pokemon Leaf green

Answer 1

The next crystal? The sapphire plate is located on island six in the builidng use cut on the door and enter. Drop down the holes in the correct order (I forget it precisely..) and a scientist will steal it from you and give you the second rocket password. Go to the rocket hideout and face the rockets inside. after facing the boss, talk to the scientist and defeat him in battle. He'll then give you the sapphire plate.

The unown you can just capture, nothing special to it.