Hey [mention]ManuSan[/mention] ,
sorry for the inconvenience you experienced. Unfortunately we can not help to evolve specific area based Pokemon like in your case, Leafeon.
You can find this information at the start of our Evolution Request Megathread.
I'm sorry to have to inform you of this. I hope you still have a great weekend! :)
So what person need do then if he is new to Main Type Pokémon Games, so he thought new Eeveelutions evolve in same matter like old ones via stones (he thought that Eevee evolves to Leafeon via Leaf Stone) and in-game Pokédex doesn't include information about evolutions?