The established premise is that Superman and other Kryptonian characters are susceptible to its radiation, which created usage of the term in popular culture as a reference to an individual's perceived weakness, changes their personality, irrespective of its nature, similar to the term "Achilles' heel".
An unpublished 1940 story titled "The K-Metal from Krypton", which Superman creator Jerry Siegel himself wrote, featured a prototype of kryptonite, a mineral from the planet Krypton that drained Superman of his strength while giving humans superhuman powers.
A mineral actually named "kryptonite" was introduced in the story arc "The Meteor from Krypton" in June 1943 on The Adventures of Superman radio series. Since radio shows had to be performed live, when Clayton "Bud" Collyer, the actor who played Superman and Clark Kent, wanted to take a vacation from the series, Superman was placed in a kryptonite trap, and a stand-in groaned with pain for several episodes until Collyer came back from his vacation.
In 1949, kryptonite was incorporated into the comic mythos with issue #61 of Superman. In August 1993, pioneering female editor Dorothy Woolfolk stated in an interview with Florida newspaper Today that she had found Superman's invulnerability dull, and that DC's flagship hero might be more interesting with an Achilles' heel such as adverse reactions to a fragment of his home planet.
Kryptonite gradually appeared more frequently, causing science fiction writer Larry Niven to theorize in tongue-in-cheek fashion that Krypton was in fact a Dyson sphere or a cold neutron star, and that this was the underlying reason for so much of the mineral finding its way to Earth courtesy of meteor showers. In an effort to reduce the use of kryptonite in storylines, all known forms on Earth were transmuted into "k-iron" in a 1971 story arc titled "The Sandman Saga".
Various forms of the fictional mineral have been created in the Superman publications:
Originally red in color, the mineral debuted in Superman #61 (November 1949) and did not adopt its characteristic green hue until Action Comics #161 (Aug. 1951). Green kryptonite weakens Superman and other Kryptonians. The character has been shown to become immune to the effects of green kryptonite due to either repeated non-fatal exposure, continuous long-term absorption of solar radiation, or extremely high short-term exposure to the sun.Post-Crisis sources establish that green kryptonite is also harmful to humans given sufficient long-term exposure, resulting in cancer as Lex Luthor discovered as a result of a ring with a kryptonite jewel he wore to ward off Superman's presence.
Debuted in Adventure Comics #252 (Sept. 1958). Originally it simply weakened Superman, but to a greater degree. Later, it was described as causing bizarre behavior and transformations. TV adaptations have traditionally shown red Kryptonite to make Kryptonians dangerously uninhibited and narcissistic.
Debuted in Action Comics #252 (May 1959). Harmless to Kryptonians, but has the same effect as the green variety on normal humans. The power source for one version of the character Ultraman, Superman's evil counterpart.
Debuted in Action Comics #261 (Jan. 1960). Created by the character Supergirl in an unsuccessful attempt to find an antidote to green kryptonite. Harmless to Kryptonians, the mineral gives normal life-forms superhuman abilities, as in the case of Supergirl's pet cat Streaky. Revised in Superman Family #203 (Oct. 1980) to have the same effect as the green variety on kryptonians.
Debuted in Superman #140 (Oct. 1960). An "imperfect" form of kryptonite which affects the imperfect character Bizarro in the same way the green variety of kryptonite affects Superman. It also affects members of the Bizarro League in the same way. Blue kryptonite is the antidote to the random and bizarre effects of Red kryptonite.
Debuted in Adventure Comics #279 (Dec. 1960). Kills all plant life, from any world.
Red-Green: first variety
Debuted in Action Comics #275 (April 1961). An alloy created by the villainous character Brainiac, it caused Superman to mutate, temporarily growing a third eye in the back of his head.
Debuted in Adventure Comics #299 (Aug. 1962). Kryptonite affected by atomic radiation, and capable of permanently removing a Kryptonian's ability to process yellow sunlight, which in turn nullifies all superhuman abilities. Post-Crisis, this kryptonite only removes a Kryptonian's powers temporarily.
Debuted in Superman #162 (July 1963). An imaginary story in which Superman combines the minerals to power a device to boost his intelligence. An explosion causes a mishap and the character is split into two separate beings ("Superman-Blue" and "Superman-Red"), both of whom possess enhanced intelligence.
Debuted in Superman's Pal, Jimmy Olsen #70 (July 1963). Revealed by Jimmy Olsen to be a hoax. In Superman/Batman #46 (April 2008), silver kryptonite was re-introduced, on this occasion shown to be authentic as it causes Kryptonians to suffer from altered perceptions, loss of inhibition, and extreme hunger cravings.
Debuted in Action Comics #310 (March 1964). Fragments of Krypton's Jewel Mountains. Amplifies the psychic powers of the criminals imprisoned in the Phantom Zone, allowing the characters to project illusions or perform mind control.
Debuted in Superman's Pal, Jimmy Olsen #80 (Oct. 1964). Affects humans the same manner that red kryptonite affects Kryptonians.
Red-Green : second variety
Debuted in Superboy Comics #121 (June 1965). This caused Superboy to lose his powers permanently, but Phantom Zone criminal Vakox unwillingly cured him, restoring his powers.
Debuted in Superman #178 (July 1965). Temporarily deprives Kryptonians of their memories.
Debuted in Superman's Pal, Jimmy Olsen #92 (April 1966). Artificially created by the villain Mr. Nero, the mineral is magnetically attracted to all substances originally from Krypton.
Debuted in Superman #192 (Jan. 1967). An imaginary story in which the alloy permanently removes the character's abilities and memories of ever having been Superman.
Debuted in The Brave and the Bold #175 (June 1981). A modified variety of green kryptonite produced by supervillan Metallo that affects humans in a manner similar to the green mineral.
Debuted in The Adventures of Superman #511 (April 1994). A one-time fluke, Kryptonite-X was created when the character the Eradicator filtered a harmful barrage of kryptonite discharged by the villain Cyborg Superman at Superman. The result was actually beneficial: "supercharging" the character and restoring his ability to process solar radiation.
Debuted in Supergirl vol. 4 #79 (April 2003). Seemingly turns Kryptonians gay. This type of kryptonite was mentioned in a single panel in a story that was a satire of the plots of the many Silver Age comic stories (such as those above in this list) which featured some strange new form of kryptonite.
Debuted in Supergirl #2 (vol. 5, Oct. 2005). Can split a Kryptonian into two separate entities: one good and the other evil.
Debuted in Krypto the Superdog #4 (Feb. 2007). Gives super abilities to any animal that comes into contact with it for 24 hours.
Debuted in Superman Family Adventures #9 (March 2013). A non-canon story, exposure causes Kryptonians to lose all inhibitions.
Other varieties of the mineral have appeared but have been revealed to be hoaxes, such as yellow (Action Comics #277, June 1961), "kryptonite plus" (Superman's Pal, Jimmy Olsen #126 Jan. 1970) and "blood" (52 #13, Aug. 2006).
Superman III (1983): billionaire Ross Webster (Robert Vaughn) orders the creation of synthetic kryptonite. Computer programmer Gus Gorman (Richard Pryor) uses tar to compensate for an unknown component of kryptonite, causing the newly created mineral to eventually turn Superman evil and split the hero into two beings. Gorman's "super computer" later fights Superman and uses a kryptonite ray.
Superman Returns (2006): Lex Luthor (Kevin Spacey) steals the Addis Ababa L9 Pallasite Meteorite and uses it to create a new kryptonite landmass and a dagger for use against Superman.
Batman v Superman: Dawn of Justice (2016): Kryptonite is discovered by men working for Lex Luthor (Jesse Eisenberg) at the bottom of the Indian Ocean and experimented with by Luthor, who learns of its harmful effect on Kryptonians when the corpse of General Zod is exposed to it. Kryptonite is stolen from Luthor by Batman (Ben Affleck), who uses it to create kryptonite gas pellets and a kryptonite-tipped spear, both of which he later uses in a battle with Superman. Doomsday is also shown to be weakened by kryptonite, allowing Superman to use the spear to kill him in the film's climax.
Adventures of Superman (1952-1958): episodes "Panic in the Sky", "The Defeat of Superman" (both 1953), "Superman Week", "The Deadly Rock" (both 1955), "The Magic Secret", "The Gentle Monster" and "All That Glitters" (all 1958) all feature kryptonite.
Superboy (1988-1992) featured green kryptonite the episodes "Kryptonite Kills" and "Metallo" (both 1989), "Bride of Bizarro" (1990), "Kryptonite Kid" (1991) and "Obituary for a Super-Hero" (1992); red in "Super Menace" (1990) and a Bizarro White variant in "The Battle With Bizarro" (1989), which heals the title character.
Lois & Clark: The New Adventures of Superman (1993-1997) featured green kryptonite in several episodes, including "The Green, Green Glow of Home", "Barbarians at the Planet", "The House of Luthor" (all 1993) "Metallo" (1994), "Top Copy" (1995) and "Battleground Earth" (1996), with the red variety appearing in "Individual Responsibility", "Ultrawoman" (both 1995) and "Lethal Weapon" (1997).
Smallville (2001-2011) featured kryptonite on a regular basis: a large quantity of the green variety descends to Earth in meteor shower, arriving in the town of Smallville, Kansas with the spaceship containing the infant Kal-El. The mineral is colloquially referred to by Smallville residents as "meteor rock", but is eventually called "kryptonite" by Clark Kent once he discovers his origins ("Rosetta", Season 2, 2003). Aside from being harmful to Clark Kent, the mineral produces bizarre changes in flora and fauna, including occasionally bestowing metahuman abilities on humans. These people are commonly known by the inhabitants of Smallville as "Meteor Freaks". The green variety of the mineral appears in several episodes every season, although other varieties appear, including red ("Red": 2002. "Exodus", "Exile", "Phoenix" : 2003, "Unsafe": 2005, "Crimson": 2007, "Upgrade": 2010), black, formed when superheating green kryptonite ("Crusade": 2004, "Doomsday": 2009), silver ("Splinter": 2005), blue ("Blue": 2007, "Persona": 2008, "Kandor": 2009, "Salvation": 2010, 'Harvest": 2011), gem ("Persuasion": 2010) and gold ("Prophecy", "Finale": 2011). Smallville was the first appearance of a Black kryptonite that would split a person into their Good and Evil halves, before later being brought into the comic canon in Supergirl #2 (vol. 5, Oct. 2005), though the concept of being split into good and evil personas had been previously used.
Supergirl (2015–present): in the series' pilot, Kara is shot down by a low-level green kryptonite tranquilizer made by the Department of Extra-Normal Operations, and is placed on a gurney with green kryptonite handcuffs. In "Stronger Together", a room with low level kryptonite radiation is used to train Supergirl in fighting without her power. Later, Hank Henshaw uses a kryptonite knife on Astra Zor-El. When Astra brings the knife to a scientist, he is unable to determine its origin, only stating it is not from Earth and that it emits specific radiation damaging to Kryptonian cells, which suggests Kryptonian experience with the substance was limited or none before their planet's destruction. By the episode "Hostile Takeover", the Kryptonians have managed to develop a wearable device blocking the radiation. DEO was shown to use kryptonite radiation guns in addition to the darts. In the episode "Bizarro", the DEO attempts to use kryptonite bullets on the titular character, but it only serves to disfigure and apparently strengthen her. However, the DEO manages to synthesize a substance with reversed ionic charge and opposite properties (blue kryptonite) which proves effective in taking Bizarro down. In the episode "For the Girl Who Has Everything", the DEO once again use green kryptonite to battle the evil Kryptonians, with Alex using a kryptonite sword to kill Astra. The Red variety appears in the episode "Falling", as a failed attempt to recreate green kryptonite by Maxwell Lord. After an accidental exposure, Supergirl first merely became uninhibited, much like the effects in Smallville, but later, became outright violent and paranoid. The effects seemed permanent until she was shot by a device developed by Lord for the purpose. The episode "The Adventures of Supergirl" reveals that Superman had stopped working with the DEO after their discovery of kryptonite, since he disagreed with them deciding to keep the material for future use.
Super Friends (1973-1986) featured kryptonite in the episodes "Superfriends: Rest in Peace" ("Krypton Steel"); "Darkseid's Golden Trap" (gold); "Terror From the Phantom Zone" (blue, green, and red); "Return of the Phantoms" (green); "Rokan: Enemy from Space" (green); "Bazarowurld" (red and blue); "Revenge of Bizarro" (red and blue); Will the world Collide?" (green); "Uncle Mxyzptlk" (red); "The Death of Superman" (green); "Batman: Dead or Alive" (green).
Superman (1988) features a kryptonite ring, worn by Lex Luthor.
The Young Justice (2010-2013) episode "Auld Acquaintance" features use of the green variety.
In Batman: The Brave and the Bold episode "Battle of the Superheroes!", Superman is infected with a Red Kryptonite necklace secretly given to Lois Lane by Lex Luthor which causes Superman to become evil. Now Batman must work with Krypto the Superdog to hold off Superman until the effects of the Red Kryptonite wear off.
Superman: Atari 2600 (1978): Luthor has created kryptonite satellites and scattered them around Metropolis that take away Superman's ability to fly when touched. Superman must then walk around Metropolis until he finds and meets Lois Lane, to regain his power.
Superman 64 (1999): appears as kryptonite fog, coined as an excuse for the game's poor draw distance.
Injustice: Gods Among Us (2013) features a kryptonite laser designed as a failsafe against Superman. In the alternate timeline, it was created by Batman, but he sealed it in the Batcave and programmed it to only be accessible when he was accompanied by four other members of the Justice League- Wonder Woman, Green Lantern, Aquaman and Green Arrow- to ensure that he couldn't make the decision to kill Superman himself, requiring him to bring in the heroes of an alternate universe to help him when Green Arrow was killed and the other three joined Superman's team. Although Lex Luthor attempts to deploy the laser against Superman, it is damaged in a fight with Captain Marvel before he is killed by Superman.
^McAvennie, Michael; Dolan, Hannah, ed. (2010). "1970s". DC Comics Year By Year A Visual Chronicle. Dorling Kindersley. p. 144. ISBN978-0-7566-6742-9. New editor Julius Schwartz, new scripter Denny O'Neil, and regular artist Curt Swan removed the Man of Steel's greatest weakness from the face of the Earth.