Mined from within the confines of the Sigil system, the Sigil crystal represented a significant investment, yet its value was justified by the intense burning sensation it induced when correctly integrated into a lightsaber. Exhibiting a brownish-yellow hue in its natural state, its application within a lightsaber resulted in the generation of an exceptionally powerful beam, inflicting enhanced harm. A Jedi known as Nemo possessed such a crystal, as did the Sith Lord named Marka Ragnos.