Meleenium was a substance found naturally only on the high-gravity planet of Af'El. This mineral was used in trace amounts for the production of durasteel. During the Imperial era, Vulca Minerals sent one ship a year to Af'El to trade fresh foodstuffs to the Defel in return for small amounts of this rare substance.
- The New Jedi Order: The Unifying Force (First mentioned)
- Galaxy Guide 4: Alien Races
- Galaxy Guide 4: Alien Races, Second Edition
- Cracken's Rebel Operatives
- "Wanted by Cracken"—Star Wars Adventure Journal 10
- Galaxy of Intrigue