Adegan crystals were commonly used by Jedi as a main component of a lightsaber. These rare Force-reactive stones were primarily found in the Adega system, though a fair amount of these crystals could also be found on the planet Halm. Other known locations where Adegan crystals could be found included Mygeeto and in parts of the Cularin system asteroid belt. During the Cold War, the Sith Empire discovered a way to utilize Adegan crystals to create a stealth armada. After the execution of Order 66, the Galactic Empire banned possession of all crystals capable of use in a lightsaber.