Life Crystal

The Life Crystal permanently increases the player's maximum health by 20, creating another heart "container" on their life bar. It also heals the player 20 health points, equal to a Mushroom.

Life Crystals are obtained by smashing a Crystal Heart with a Hammer.

Maximum health can be increased up to 20 hearts, or 400 health points. If used at maximum, a Life Crystal will not have any effect, though the same animation will commence. Doing this won't consume the Life Crystal, nor will it restore any health.

Trivia

 * In the alpha version, bosses dropped life crystals.