Armageddon Sapphire

The Armageddon Sapphire was a superweapon created by the Time Lords and stored in the Slaughterhouse on Gallifrey.

It was considered the ultimate weapon by the Gallifreyans, capable of tearing reality apart and causing the Higher Place to collapse into Calabi-Yau Space. This made it capable of destroying the basic particles of the Universe, making way for a new Universe. Once the process began, it could not be stopped. (PDA: The Quantum Archangel)