Luxum

A Luxum crystal was a type of crystal that could be used in lightsaber construction. These crystals were from the world of Ambria, a planet gripped by dark energies, where they were formed out of the minerals and Force energy contained in Lake Natth through long and deep meditation. They were more effective against droids, imparting an ion effect to a lightsaber blade when used the construction of the weapon. Luxum crystals were one type of mineral sought out by fugitive Jedi Jax Pavan in his search for a mineral with which to construct a new lightsaber after losing his in a fight with Darth Vader.