A whetstone.
togetic
If you are referring to Pokemon, the game for the Gameboy then yes you can evolve your Pokemon using a moon stone, If how ever you are talking about finding a moon stone here on earth in real life,...
Pikacu to Richu ( thunder stone ) , Eevee to alot , Staryu to Starmie ( water stone ) , Skitty to Delcatti ( moon stone ) .
poliwhirlstarulombre