You can find the Oval Stone in the Lost Tower in Pokémon Diamond, Pearl and Platinum. Additionally Pokémon with the Pickup ability have a chance of picking it up if the Pokémon is Level 51 or higher.
let happiny hold the oval stone and train it one level and it will evolve
Happiny
Only Happiny can evolve using an Oval Stone. Happiny will have to hold it during the day, then level it up to allow it to evolve into Chansey.
With an oval stone, you can evolve Happiny into Chanssey.But, you need to make Happiny hold that stone and then level it up in order to evolve.
You can evolve happiny with an oval stone after its friendship is high
It evolves Happiny. When Happiny levels up during the daytime while holding the Oval Stone, it will evolve into Chansey.
haPPINY
happiny
happiny into Chansey
just happiny
Happiny, GIVE, not use, give Happiny the oval stone when she likes you a LOT, and level her up. that is not really true my happiny LOVES me alot and i gave her a oval stone and she did not evolve. But though my game is pearl.
You can evolve Happiny into a Chansey if Happiny is holding the oval stone and leveled up during the day.