|Owner(s)|| Lex Luthor|
|User(s)|| Lex Luthor|
|Appeared in|| Superman: The Serial|
Atom Man vs. Superman
Superman: The Movie
Justice League: Crisis on Two Earths
Kryptonite is the ore form of a radioactive element from Superman's home planet of Krypton. The most common variant is colored green. When exposed to regular Kryptonite on Earth, Kryptonians lose their powers. When exposed to other types there are various effects.
Lex Luthor and his cronies Eve Teschmacher and Otis track a large chunk to Addis Ababa, Ethiopia, where they steal it from a museum under the cover of night. In this film's usage, the term "kryptonite" seems to mean simply a "Kryptonian meteorite". After co-opting and launching two missiles for opposite ends of the United States, Luthor places the kryptonite on a chain around Superman's neck and drops him into a swimming pool. When Teschmacher learns that one of the missiles is headed for Hackensack, New Jersey (where her mother lives), she rescues Superman from drowning and removes the kryptonite, after which his strength and powers quickly return.
Billionaire Ross Webster orders the creation of synthetic kryptonite after remembering a Daily Planet story about the last original chunk disappearing years earlier after falling to Earth. After scanning the coordinates of Krypton's former location via satellite, computer programmer Gus Gorman determines that kryptonite is "an intense heat fusion" of: 15.08% plutonium, 18.06% tantalum, 27.71% xenon, 24.02% promethium, 10.62% dialium (which is a plant genus, not an element), 3.94% mercury, with the last 0.57% being an unknown element not found on the periodic table. The substitution of tar (which Gorman used after glancing at a pack of cigarettes) for the crucial, but unknown, component resulted in the synthetic kryptonite - like black kryptonite in the DC comics - turning Superman evil and eventually splitting him into two people. Retaining Superman's remaining good qualities, Clark Kent defeats the dark Superman, who vanishes. Later in the film, Gorman's creation, the Ultimate Computer, severely weakens Superman with a kryptonite ray before Gorman has a change of heart and attacks his own machine.
Lex Luthor enters the Metropolis Museum of Natural History and steals the Addis Ababa L9 Pallasite Meteorite, which was discovered at the Kebe Mine in Addis Ababa, Ethiopia. It is described in the exhibit display as “sodium lithium boron silicate hydroxide with fluorine”. According to the exhibit display, the meteorite was discovered in 1978 - the year that Superman: The Movie was released.
Incidentally, in 2007, a white and harmless mineral with the above chemical formula (except without fluorine) was discovered by Rio Tinto Group researchers in a mine in Serbia.
Luthor uses the meteorite in his quest to create a new kryptonite landmass. In addition, he uses a shard leftover from processing it to create a kryptonite shiv, which he uses to stab Superman.
Blue Kryptonite makes a brief appearance. As the heroic Lex Luthor of the parallel universe battles his arch enemy Ultraman (that universe's evil Superman), he is beaten but, gains the upper hand by revealing, and weakening Ultraman with a piece of blue kryptonite, the only thing he is vulnerable to (mirroring Superman's weakness to the green variety). When confronted by it Ultraman is severely weakened, and claims to have destroyed all the pieces of it left; Lex admits that Ultraman did, but that he himself has been to other universes and gotten more.
Kryptonite was used in both 15 part movie serials produced by Columbia Pictures. The Spider Lady and her gang use Kryptonite against Superman in Superman (1948). Lex Luthor, the Atom Man, creates a synthetic Kryptonite to use against Superman in Atom Man vs. Superman (1950).