Ryll kor was the rarest grade of ryll. It made up approximately three percent of all ryll. Ryll kor absorbs light except in the ultraviolet range which gave it an appearance of charcoal black except to someone who can see in ultraviolet range.
- X-Wing: The Krytos Trap
- Hutt and Seek
- Junior Jedi Knights: Kenobi's Blade (Mentioned only)
- The New Jedi Order: Agents of Chaos II: Jedi Eclipse