Ilum Crystals
similar in many respects to Adegan crystals, Ilum crystals were favored by the Jedi Knights of the Old Republic for use in the creation of lightsabers. Found growing on the remote world of Ilum, each crystal had to be located and harvested by a Jedi Padawan who faced the challenges of weather and nature to obtain the crystal. Ilum crystals almost always produced a lightsaber blade that was blue or green in color, and were nearly uniform in their stability and power-handling capabilities. This, coupled with their ready availability on Ilum and the presence of a Jedi base on Ilum, made Ilum crystals the primary choice for lightsaber construction during the last decades of the Old Republic. This meant that virtually every Jedi had a lightsaber with a blue or green blade. Unfortunately, the Jedi facilities on Ilum were destroyed during the Clone Wars, cutting off this sourse of lightsaber crystals for the Jedi of Luke Skywalker's Jedi praxeum.