What do all the stones do in Pokemon SoulSilver?

Stones have many different effects on different Pokemon. If you give a Pokemon the everstone it is prevented from evolving. However, stones can also be used to evolve certain Pokemon. In order for poliwhirl to evolve into poliwrath, you need to give it a water stone. Stones need to be matched to the type of Pokemon you are using them on. Leaf stone to grass types, fire stone to fire types, and thunder stone to electric types and so on. Not all Pokemon evolve using stones. Starters cannot evolve using stones. That's all you need to start evolving Pokemon through stones.