There is a King's Rock hidden somewhere in Celestic Town - the left ledge of the pit in the town centre, if I remember correctly; use the Item Radar.
It can also be found (rarely) with the Ability Pickup by a Pokemon of a level from 11 to 30.
a grass Pokemon
i think eevee
you cant get one
happini can evolve with a oval stone
if you have a pokemon with strength use the move to push the stone into pit
You don't get the magna stone from buck in Pokemon platinum.
It does not evolve with a dusk stone in Pokemon Platinum
there is no bronze stone
a grass Pokemon
The Pokemon that can use oval stone in Pokemon platinum is Happiny. It is the pre evolve form of chansey. Mostly every chansy you catch have a oval stone.
eevee
underground
underground
Happiny evolves into Chansey with an Oval Stone.
toolmon obviously
i think eevee
no Pokemon evolves with a fire stone in Pokemon platinum except eevee which turns in to flareon