A kyber crystal, simply known as a kyber, also called a lightsaber crystal, the living crystal, and known in ancient times as a kaiburr crystal, were rare, Force-attuned crystals that grew in nature and were found on scattered planets across the galaxy. They were used by the Jedi and the Sith in the construction of their lightsabers. As part of Jedi training, younglings were sent to the Crystal Cave of the ice planet of Ilum to mine crystals in order to construct their own lightsabers. The crystal’s mix of unique luster was called «the water of the kyber» by the Jedi. There were also larger, rarer crystals of great power and that, according to legends, were used at the heart of ancient superweapons by the Sith.
The Most Powerful Defensive Kyber Crystal Ever Discovered. The Solari Kyber crystal was a very rare type of lightsaber crystal that when placed inside of a lightsaber, formed an extremely wide blade. This wide blade made it far easier to block blaster bolts and aim those deflected bolts more accurately. The crystals would usually only call to force users deeply attuned to the light side, and would even begin to shrink when that force user strayed to the dark side.