Resurrection crystals

Resurrection crystals were small round marbles of diamond. Each one held part of the life force of every Jedi or Sith that had ever lived. They could be dissolved in water. Upon dissolving, the Jedi or Sith that the crystal held host to would be resurrected. Sith ressurection crystals usually made the mind of the Sith unstable for months after resurrecting, which was called resurrection madness.