[Source] Cordylleum was an explosive substance that was stored in kegs. During the Rebellion on Akiva, the New Republic Special Forces Sergeant major Jom Barell mentally compared the rising anti-Imperial sentiment and tension amongst the population of the city of Myrra to a keg of cordylleum that was about explode. Shortly after, the population rose up against the Empire, aiding the New Republic and its allies in defeating them and driving them off the planet.