If you remember where Bill's house is in Red, Blue, and Yellow (North of Cerulean) then go to that house and talk to Bill's dad, he'll ask you to find Pokemon for him. He'll give you a stone corresponding the Pokemon's element... From memory I know he wants a Lickatung, Pichu, Tangela, Growlithe, and I am 90% sure on a Staryu.
Exchange Blue Shard with the Waterstone. You'll find waterstone in Abandoned Ship, too.
Poke'athalon
You can get waterstone in route 25 at Bills cottage you will see Bills grandfather ( Likitounge (everstone)oddish(leafstone)staryu(waterstone)growlithe(firestone)pichu(thunderstone)
only vapreon
For which game? Pokemon Red Pokemon Blue Pokemon Yellow Pokemon Gold Pokemon Silver Pokemon Crystal Pokemon Sapphire Pokemon Ruby Pokemon FireRed Pokemon LeafGreen Pokemon Emerald Pokemon Diamond Pokemon Pearl
lombre and staryu.
I know poliwhirl will evolve to poliwrath and that shelder will evole to cloyster with the waterstone
You can buy one with Athlete Points at the Pokeathlon Store on some days, or you can get a Waterstone from Bill's grandfather after you show him a certain Pokemon.
Dig it out in the underground.
You Need A Waterstone.
Its evolve to Vaporeon from eevee
buy it in celdon city