Purification Powder

Purification Powder can be bought from the Dryad for 75 copper each and can be used to return corrupt blocks to normal, such as Ebonstone to Stone, Ebonsand to Sand and corrupted grass to normal grass, as well as destroying corruption thorns. Using this or Dynamite is currently the only way to get to Shadow orbs and break them without having to defeat Eater Of Worlds.