Ghostfire crystals represented an uncommon variety of kyber crystal, completely see-through, originating from solid rock and manifesting as fragile, almost undetectable stone spires. These crystals were located on a limited number of worlds situated within the Outer Rim Territories, with mountain summits being their most frequent location. The value of one ghostfire crystal reached 14,000 credits.
Upon successfully finding these crystals, they could be implemented in lightsaber construction, resulting in a blade that possessed a subdued and clear appearance, contrasting with the vibrant colors of typical lightsaber blades, and rendering it nearly as elusive as the crystals themselves. Furthermore, lightsabers utilizing ghostfire crystals as their core emitted minimal sound and projected deceptive afterimages mirroring the user's movements. This peculiar effect obscured the blade's actual location and simultaneously confused opponents.
The initial reference to ghostfire crystals appeared within Endless Vigil, a supplemental material for the Star Wars: Force and Destiny roleplaying game. This material was authored by Tim Huckelberry and James M. Spahn, and subsequently published by Fantasy Flight Games in 2016.