If you're asking about the blue crystal in Pokemon Ranger Shadows of Almia, then it's at the top of Almia Castle. To get there you surf with a Floatzel through Crysta Cave then go through Hia Valley then surf through the icy lake and then go all the way to the top of the castle and fight Lucario and then you'll have it.
Shadows of Almia
97 is eevee.
Sorry you can't
right behind you if you capture any
you have to beat darkria
Peril Cliffs.
Special mission on the Ranger net
get a stuntank
you go to the beach
In the oil feild hideout.
beat mission 5
i like big round donuts