Recrystallization was the process of matter being reorganized into crystalline form.
Dilithium crystals could be recrystallized with various technologies. One such device was a dilithium incubator created by the Xahean Me Hani Ika Hali Ka Po. (ST: "Runaway"; DIS: "Such Sweet Sorrow")
Starfleet did not have the ability to recrystallize dilithium until at least the 2280s. During a time travel mission from 2286 to 1986, Spock and Montgomery Scott developed a method of recrystallizing dilithium through exposure to high-energy photons from the toxic nuclear fission reactors of that era. (Star Trek IV: The Voyage Home)
In the 24th century, the theta-matrix compositor aboard the Galaxy-class starship USS Enterprise-D made the recrystallization process of dilithium ten times more efficient than on the older Excelsior-class ships. (TNG: "Family")
The Enterprise-D recomposited fractured dilithium crystals while they were still inside the articulation frame. (TNG: "Relics")
By the 2360s, Starfleet had the ability to synthesize dilithium via recrystallization while it was still enclosed in the warp core's dilithium articulation frame using a theta-matrix compositor. This was done by recompositing fractured crystals. (TNG: "Time Squared", "Relics"; VOY: "Innocence")
The reaction chamber of the USS Voyager was equipped with a compositor that allowed the recrystallization of dilithium. While stranded in the Delta Quadrant, the crew could never be sure when they'd be able to find a new supply. (VOY: "Innocence")
In the 32nd century, Cleveland Booker had a dilithium recrystallizer aboard his ship. (DIS: "That Hope Is You, Part 1")
In the script of Star Trek but not the final version of that film, the prime version of Montgomery Scott was said to have discovered not transwarp beaming, but the correct field equation to recrystallize dilithium, which was what made transwarp beaming possible.