The Heal Crystal is a block beneficial to players added by Advanced Genetics. If the player is within a radius of 9 blocks from the Heal Crystal, it will immediately start healing them until they reach full health. If the player has the Ender Health ability taken from an Ender Dragon, the range the Heal Crystal heals from is increased to a 20 block radius.
Heal Crystals are very similar to the Health Crystals found in The End when battling the Ender Dragon, but instead of healing the dragon, the Heal Crystal will only heal players. Mobs do not receive healing from this block. Only the player who placed the Heal Crystal can break it.