Use an Orb of Chances

An Orb of Chance is a rare gemstone-like item that offers a chance to evolve a normal item into a unique item, or outright destroy the item. It’s a gamble. You can obtain an Orb of Chance by:
Disenchanting magical equipment and items by speaking to Una (Act 1), Zarka (Act 2), or Servi (Act 3).
Slaying enemies throughout any zone in the game.
Visit a Currency Exchange NPC, which unlocks upon Cruel Difficulty after finishing Act 3 on Normal.