Purple Gems are Refined Items crafted with 1 Red Gem and 1 Blue Gem. The Prestihatitator is required to unlock the crafting recipe. It can also be dropped by the two variants of the Clockwork Bishop when killed. Ancient Statues can also drop it when mined. Maxwell starts out with one purple gem, among other items.

It is used to make the Shadow Manipulator, Bat Bat, Telelocator Staff and Nightmare Amulet. A quantity of 3 Purple Gems are also required to be installed in the Telelocator Focus before it will work to teleport a mob or the player themselves.