Aztec Moonstone

The Aztec Moonstone was a powerful object harnessed by Jolly Roger, to use the power of a cursed-looking 'Muertos Moon', to make the atmosphere of the Caribbean green and hazy, and so that pirates would fight with each other till death, in the Curse of the Muertos Moon. The object apparently might have been cursed by Aztec Gods, just as what happened with the Chest of Cortes. However, after days of the Curse, Captain Jack Sparrow had taken the object from one of Jolly Roger's minions, and mysteriously reverted back the Curse.