Before an alchemist can perform transmutations, he or she must create a Philosopher's Stone. This stone must be in the inventory or equipped to perform any transmutations, and it is not consumed when a transmutation is done. Iron (and lead), gold, silver, and mithryl can all be transmuted into gold, true gold, alchemical silver, and truesilver respectively. Titanium also must be transmuted from Titanium Ore.Elemental essences can also be transmuted. Essence of Undeath can be transmuted to Essence of Water, Essence of Water can be transmuted into Essence of Air, and so on. Primal ingredients may also be transmuted. Primal Earth to Primal Water to Primal Air to Primal Fire to Primal Earth; Primal Shadow to Primal Water to Primal Shadow; Primal Fire to Primal Mana to Primal Fire; Primal Earth to Primal Life to Primal Earth. You can also transmute Primal Fire, Air, Earth, Water, and Mana into Primal Might. Transmutation of Eternal ingredients can also be attempted (see diagram): Eternal Life to Eternal Fire or Eternal Shadow; Eternal Fire to Eternal Life or Eternal Water; Eternal Water to Eternal Fire or Eternal Air; Eternal Air to Eternal Water or Eternal Earth; Eternal Earth to Eternal Air or Eternal Shadow; and lastly Eternal Shadow to Eternal Life or Eternal Earth.
1. Alchemy -- World of Warcraft Wiki: Transmutation.