Kaiburr
this unusual crystal was considered by the ancient Jedi Knights to be one of the most powerful stones that could be used as a focusing lens in the construction of a lightsaber. The use of a kaiburr stone was supposed to give a Jedi added insight and fortitude. The best-known example of this mineral was the appropriately-named Kaiburr Crystal, which was pursued for many years by Darth Vader.