There is not one, but you can attach it to a poke'mon from Fire Red or Leaf Green. Same with Fire stones. You can get unlimited stones from Fire Red and Leaf Green.
you cannot buy a water stone
you can use a water stone on lombre
abandoned ship
You use a WATER STONE on Lombre to get Ludicolo.
get a life. then get it at the abandoned ship!
You can't get Lucario in Ruby, Saphire or Emerald. Diamond, Pearl and Platinum only. sorry....
It evolves by use of a water stone, level has nothing to do with it.
On the abandoned ship.
You can't in Ruby, Sapphire, or emerald, you have to look for them.
Evolve a lotad then use a water stone on lombre.
Lombre and etc
all you need is a blue shard and go to the shard maniac just of mossdeep and he will give you a water stone and a water stone can evolve starmie, and lotad :)