Rubat was a variant of kyber crystal used in the construction of lightsabers. The planet Phemis was the only known source of rubat.
When placed in a lightsaber's crystal chamber, rubat sharpened the appearance and definition of the blade, allowing its wielder to easily track the blade and strike opponents properly. The crystal would also help its wielder attack faster.
The use of rubats was controlled by the Galactic Senate, and later the Galactic Empire. The Jedi Order exclusively used rubats before switching to crystals from Ilum.
This crystal is used in Star Wars: The Force Unleashed and slightly increases lightsaber damage.
In Star Wars: Knights of the Old Republic, it provides a +1 to attack modifier and a +1 to lightsaber damage
- Star Wars Knights of the Old Republic: Prima's Official Strategy Guide
- Star Wars: Knights of the Old Republic II: The Sith Lords: Prima Official Game Guide
- Knights of the Old Republic Campaign Guide
- The Complete Star Wars Encyclopedia
- Jedi Academy Training Manual
- Suns of Fortune