The Durindfire gem is a precious crystal found on the planet Tatooine.
Few Durindfires ever leave the planet, though some were bought and sold by the Galactic Empire to help finance the Death Star project. The Alliance to Restore the Republic was able to pinpoint the Empire's various development sites by tracking the movement of these gems, and additionally used this information to uncover the origins of the TIE Phantom Project.
A Durindfire gem is key in adding a distinctive silver sheen to any lightsaber blade. This stone was traditionally used by the Jedi of the Halcyon/Horn family.