Mutonium was a very rare and valuable ore, found in the Stenness Node.
- Tales of the Jedi 4: The Saga of Nomi Sunrider, Part 2 (First appearance)
- The Last of the Jedi: The Desperate Mission (Mentioned only)
- Rebel Force: Trapped (Mentioned only)
- Tales of the Jedi Companion
- The Essential Guide to Vehicles and Vessels
- Star Wars Encyclopedia
- The Complete Star Wars Encyclopedia