That's right. They are... a rare type of stone with the power to make pokemon evolve.
Most pokemon will evolve simply by reaching a certain level, but some have other requirements. In particular, some pokemon seem to need the power of an evolutionary stone to change. I'm not really certain where these stones comes from, or exactly what it is about them that makes a pokemon evolve, but you can buy them in large department stores. There's ten different evolutionary stones in all, and sun and leaf stones are two of them.
A pokemon will immediately evolve after being given a stone, so it is best not to hold them while it happens.
[Unless you want to get squashed under a suddenly giant Arcanine, but Armin doesn't speak from experience or anything, nope. Not at all.
Text;
Most pokemon will evolve simply by reaching a certain level, but some have other requirements. In particular, some pokemon seem to need the power of an evolutionary stone to change. I'm not really certain where these stones comes from, or exactly what it is about them that makes a pokemon evolve, but you can buy them in large department stores. There's ten different evolutionary stones in all, and sun and leaf stones are two of them.
A pokemon will immediately evolve after being given a stone, so it is best not to hold them while it happens.
[Unless you want to get squashed under a suddenly giant Arcanine, but Armin doesn't speak from experience or anything, nope. Not at all.
oh god the pain.]