Philosopher's Stone

The Philosopher's Stone is a Hardmode Accessory that reduces the 1 minute Potion Sickness debuff cooldown time by 15 seconds, so that the cooldown is only 45 seconds. Essentially this means that most regenerative Potions can be used more often. It is dropped by Mimics.

Trivia

 * The Philosopher's Stone is a legendary alchemical substance that could transmute base metals into gold or silver, and provide eternal youth and immortality. In alchemy the color crimson represents the stone.

History
May be a reference to the Philosophers stone from Full Metal Alchemist