The Orb of Transmutation is a currency item in Path of Exile that can be used to upgrade a piece of magic equipment to a rare item. It can be obtained by purchasing it from vendors, or found as a drop from monsters, chests and strongboxes.

The Orb of Transmutation can be used to upgrade any normal item to a rare item. This includes weapons, armor, shields, rings, amulets and jewels. It does not affect unique items or maps. When used, the Orb of Transmutation will randomly re-roll the item's attributes, giving it a new set of modifiers. This random re-roll can also give the item additional sockets or links.

To spend the Orb of Transmutation, the player must right-click on it and then left-click on the item they wish to upgrade. The Orb of Transmutation will then be consumed, and the item will be upgraded to a rare item. Note that this process is irreversible and the item cannot be returned to its original state.

The Orb of Transmutation is a great way to add variety to your Path of Exile character's equipment. It can also be used to target specific modifiers, making it a valuable currency item for experienced players.