i think it is a leaf stone
Fire stone
You have to use a dusk stone on it to in order for it to evolve
A water stone
murkrow and another Pokemon
Give it a dusk stone.
Use a thunder stone
You can evolve an evee which you can find in Goldenrod city.
It will only evolve through the use of a leaf stone.
sorry no stone, they evolve by level or trade
you give her a sun stone and trade her
Have a friend trade a Pokemon that is holding a dusk stone then you can evolve your murkrow
you can find a leaf stone in viridian forest in kanto in heartgold