The Radiant Jewel increases the effectiveness of healing potions by 50% making it essential in expert mode.
It also boosts healing for all regenerating items like Heart Lanterns and Campfires.
A unique version called the Ace of Harts increases critical heal potential by 10%.
You craft it using Beetle Husks after defeating Plantera in Hardmode.
It pairs well with builds centered around regeneration like modular summoner or mage playstyles.
The Symphonic Breath mod adds synergy if you swap buffs mid boss fight.