The Protective Jewelry of the Gems of Power is given to Finn and Jake by Princess Bubblegum in "Mortal Folly." Princess Bubblegum and possibly other elemental princesses and royalties in Ooo wear this jewelry. The protective qualities of it are seemingly in the gemstones. The jewelry grants the elemental wearer protection from the Lich's powerful spells, most notably his ability to control minds. Finn's jewel breaks during his encounter with the Lich, almost causing the Lich to gain control of Finn. However, Finn is protected by the power of "liking someone a lot" infused in the sweater Princess Bubblegum made for him.
- The princesses' jewels on their crowns
- Princess Bubblegum's earrings
- For Fire Elementals only: fire gem (best found on Flame Princess)
- One of three gems on Ice King's crown