Therangen was a volatile black rock used as fuel by less-technologically-advanced races. It was a dangerous substance and it reacted violently to fire. Veren Gal, an ancient Sith archaeologist, thought that the ancient Sith on Korriban used it as a power source. Revan discovered a pillar of Therangen in Ajunta Pall's Tomb, and was forced to use a grenade to destroy it to continue deeper into the tomb.