The Greater Mark of Illumination was a symbol of the Chalactan Adepts, one of the Marks of Illumination. A gold bead, it symbolized the universe and the Uncloseable Eye that saw it, and was given to those who achieved the Chalactan Enlightenment by the Convocation of Adepts. It was permanently affixed to the frontal bone of the Adept's skull, and was a larger version of the Lesser Mark.
One person who attained enlightenment was the Jedi Master Depa Billaba. However, the Summertime War of Haruun Kal greatly warped her beliefs, and she removed the bead eventually, leaving a scar.