Rubat crystals
Rubat represented a specific type of kyber crystal that found its purpose in the creation of lightsabers. The sole known location where rubat could be found was the planet of Phemis.
When a rubat crystal was integrated into a lightsaber's crystal chamber, it enhanced the clarity and sharpness of the blade's visual representation. This enhancement allowed the wielder to more easily follow the blade's movements and execute strikes against opponents with greater precision. Furthermore, the crystal contributed to an increase in the wielder's attack speed.
The Galactic Senate initially maintained control over the utilization of rubats, a control that was later assumed by the Galactic Empire. Before transitioning to crystals sourced from Ilum, the Jedi Order exclusively relied on rubats.
This crystal makes an appearance in Star Wars: The Force Unleashed, where it provides a minor boost to lightsaber damage output.
Within Star Wars: Knights of the Old Republic, this crystal grants a +1 bonus to the attack modifier and an additional +1 to lightsaber damage.