The currency system of Path Of Exile revolves around spheres and their rarity. The following are the rarest spheres in the game.
The Ancient Orb is one of the most elusive currencies in the game because it was introduced in the Pioneer League in 2017, in the original and more violent days of the Exile, hence its name "ancient".
Awakener's Orb is the craftsman's most precious tool, because the player can use it to copy the perfect item, although the original item will be destroyed. Think of it as the cut and paste ball in Path Of Exile, but it is suitable for influential items.
The diving orb is an older pioneer orb in Path Of Exile. Although more precious POE Currency have appeared, it still has value to this day. Mirror fragments are not spheres, so they have no inherent value. They are actually used to stack until the player has enough of them to become Kalandra's mirrors. Currently, their cost is approximately 5,500 Chaos Orbs.
Maven's Orb is a very precious currency. It takes about 2,800 Path of Exile Currency to purchase through transactions. As for the rarest currency in the game, it is the Mirror of Calandra. Its rarity is directly proportional to its practicality.