The Earth Plate is a held item that can be found in the Oreburgh gate by Surfing to the far left of the cave and using Rock Smash to get the PokeBall. It raises the power of Ground-type moves and makes Arceus a Ground-type when held.
Underground!
a fist plate
purple
you have to dig it up when you are underground
mining the underground do u know that www.serebii.net exists?
You can search on youtube. that's where i found mine.search Pokemon PLatinum plate locations.
It is the earth plate you can get it at the oreburgh gate or at the underground.
there is no such thing as a "Curse Plate."
Underground!
Arceus (With Dragon plate)
you can get iron plate by using explorer kit
a fist plate
The ground or Earth plate is in Mt. Coronet on the west side of Oreburgh City. It's downstairs and you need HM Surf to reach it.
purple
you have to dig it up when you are underground
if a Pokemon holds a plate (arceus) and a Pokemon uses flail the shards restore the plate because flail breaks the plate.
no there is no such thing as the polychromatic plate