Dilithium Crystals
From Starbase 900 Wiki
Crystalline substance used in warp propulsion systems aboard starships. Dilithium regulates the matter/antimatter reactions that provide the energy necessary to warp space and travel faster than light. Naturally occurring dilithium is extremely rare and is mined on only a few planets. Until the advent of recrystallization techniques that permitted the production of synthetic dilithium, the crystals were among the most valuable substance in the galaxy.
This break-through occurred in 2286 when Spock (who had traveled back in time to 1986), devised a means whereby dilithium crystals could be recrystallized by exposure to gamma radiation (high energy photons) that were by-products of nuclear fusion reactions. By the late 2360s, recrystallization techniques had advanced to the point that crystals could be recomposited while still inside the articulation frame of the dilithium chamber, extending the useful life of the crystals even further.