Kryptonite is a fictional material that appears primarily in Superman stories published by DC Comics. In its best-known form, it is a green, crystalline material originating from Superman's home world of Krypton that emits a unique, poisonous radiation that can weaken and even kill Superman and other Kryptonians. Kryptonite radiation can be transmitted through any element except lead. There are other varieties, such as red kryptonite and gold kryptonite, which have different but still generally negative effects.

Adversaries of Superman and other characters are frequently depicted using kryptonite against Superman, with Lex Luthor incorporating it into weapons, Metallo being powered by it, and Titano able to project Kryptonite radiation from his eyes. Kryptonite has become a byword for an extraordinary exploitable weakness, synonymous with "Achilles' heel".

History

thumb|upright|[[Superman suffering from green kryptonite poisoning, courtesy of foes Metallo and Titano, in Action Comics Annual #10 (March 2007), art by Art Adams and Alex Sinclair]]

An unpublished 1940 story titled "The K-Metal from Krypton", written by Superman creator Jerry Siegel, featured a prototype of kryptonite. It is a mineral from the planet Krypton that drains Superman of his strength and gives superhuman powers to humans. This story was rejected because Superman reveals his identity to Lois Lane.

The mineral kryptonite, not to be confused with the real element krypton, was officially introduced in the radio serial The Adventures of Superman, in the story "The Meteor from Krypton", broadcast in June 1943. An apocryphal story claims that kryptonite was introduced to incapacitate Superman, allowing Superman's voice actor Bud Collyer to take time off. This tale was recounted by Julius Schwartz in his memoir. However, historian Michael J. Hayde disputes this. In "The Meteor from Krypton", Superman is never exposed to kryptonite. If kryptonite allowed Collyer to take vacations, that was a fringe benefit discovered later. More likely, kryptonite was introduced as a plot device for Superman to discover his origin. Hayde may have mistaken 1943's "The Meteor from Krypton" for 1945's "The Meteor of Kryptonite", as Superman was exposed in the latter but not in the former.

In the radio serial, Krypton is located in the same solar system as Earth, in the same orbit, but on the opposite side of the Sun. This provided an easy explanation for how kryptonite found its way to Earth. In the comics' Silver Age, Krypton is located in a distant solar system and much of the kryptonite that came to Earth was transported by the same "space warp" that baby Kal-El's rocket traversed.

Kryptonite was incorporated into the comic mythos with Superman #61 (November 1949). In a 1993 interview with Florida Today, editor Dorothy Woolfolk stated that she felt Superman's invulnerability was "boring".

Originally depicted as an element in the Golden, Silver, and Bronze Age comics, Kryptonite is depicted as a compound in post-Crisis continuity.

Varieties<!-- Citations needed in the table. -->

Various forms of the fictional material have been created over the years in Superman publications and programs. This table includes forms that have not persisted in canon.

{| class="wikitable sortable sticky-header-multi" style="width:100%; font-size:84%;" id="softwarelist"

|-

! rowspan="4" colspan="2" | Type

!rowspan="4"|First appearance

!rowspan="4"|Origin

!colspan="3"|Effects by genetic origin

!colspan="5"|In other media

|-

!rowspan="3"|Krypton<hr>Daxam

!rowspan="3"|Earth

!rowspan="3"|Bizarro World<hr>Krypton-3

|-

!colspan="2"|Film

!colspan="2"|Television

!rowspan="2"|Video games

|-

!|Live-action

!|Animated

!|Live-action

!|Animated

|-

! colspan="2" style="background:lime; color:black;" | Green

| The Adventures of Superman radio serial, "The Meteor from Krypton" (June 1943) <hr>Comics: Action Comics #161 (August 1951)

|Fragments from Krypton

|Loss of superpowers<hr>Severe, intensifying pain<hr>Intensifying breathing issues<hr>Severe muscular weakness<hr>Fever<hr>Green blood or skin<hr>Eventual fatality<hr>Non-accumulative<hr>Mitigated by copious yellow sunlight exposure<hr>Blocked by lead<hr>Neutralized by Kal-El's ship (Smallville)

|With prolonged exposure: carcinogenesis<hr>Possible cancer treatment<hr>Varied (Smallville)

|Bizarro: perfect health<hr>Bizarro World humans: temporary superpowers (Superman & Lois)

|

  • Superman serial
  • Atom Man vs. Superman
  • Superman (1978)
  • Superman III
  • Superman Returns
  • Batman v Superman: Dawn of Justice
  • Superman (2025)

|

  • Justice League: Doom
  • Justice League Action
  • DC League of Super-Pets
  • Batman Ninja vs. Yakuza League

|

  • Adventures of Superman
  • Superboy
  • Lois & Clark: The New Adventures of Superman
  • Smallville
  • Arrowverse
  • Titans
  • Superman & Lois

|

  • The Brady Kids
  • Super Friends
  • Superman (1988)
  • DC Animated Universe
  • Krypto the Superdog
  • Legion of Super Heroes
  • The Batman
  • Young Justice
  • Batman: The Brave and the Bold
  • DC Super Hero Girls
  • My Adventures with Superman

|

  • Superman (1979)
  • Superman (1987)
  • Superman: The New Superman Adventures
  • Mortal Kombat vs. DC Universe
  • Lego Batman 2: DC Super Heroes
  • Scribblenauts Unmasked: A DC Comics Adventure<hr>Counteracted by green (Smallville)<hr>Stronger form of green (prior to Adventure Comics #252, September 1958 only)

|Unpredictable effects (prior to Superman's Pal Jimmy Olsen #80, October 1964 only)<hr>Hair loss (Super-Pets)

|

|

|Super-Pets

|

  • Superboy
  • Lois & Clark
  • Smallville
  • Supergirl
  • Titans

|

  • Super Friends
  • Batman: The Brave and the Bold
  • Krypto
  • Justice League Action
  • DC Super Hero Girls

|

  • Superman (1987)
  • Scribblenauts Unmasked

|

|

|

|

|

|

|

|-

!style="background: blue; color: red;" |-blue

|Superman #162 (July 1963)

|Invented by Superman<hr>Green charged with "quantum battery" (Justice League Action)

|Splitting into uninhibited red being and logical blue being

|Same as on Kryptonians (Justice League Action)

|

|

|

|

|Justice League Action

|

|-

!style="background: red; color: white;" |Bizarro-

|Superman's Pal, Jimmy Olsen #80 (October 1964)

|

|

|Bizarro humans: Ridding of Bizarro state<hr>Humans: Same as red on Kryptonians

|

|

|

|

|

|Scribblenauts Unmasked

|None

|Same as green on Kryptonians

|Ultraman: Perfect health

|

|

|Lois & Clark

|

|Scribblenauts Unmasked

| Action Comics #261 (January 1960)

|Experiment by Supergirl to counteract green<hr>Fragments from Krypton (Superman & Lois/Super-Pets)

| None

| Temporary superpowers

<hr>Paranoia (DC Super Hero Girls)<hr>Counteracted by green (Superman & Lois, Super-Pets)

|Bizarro: same as green on Kryptonians (Superman & Lois)

|

|Super-Pets/same as green on Kryptonians (Justice League: Crisis on Two Earths)<hr>Blocked by "imperfect" lead

|

|Crisis on Two Earths

|

  • Smallville
  • Supergirl

|Super Friends

|Scribblenauts Unmasked

|-

! rowspan="2" style="background:#FFFFFF|White

|style="background: white; color: black;" |

|Adventure Comics #279 (December 1960)

|Green affected by "space cloud"

|Kills microbes and vegetation

|Kills microbes and vegetation

|

|

|

|

|

|Scribblenauts Unmasked

|

|

|-

! colspan="2" style="background: grey; color: white;" |Magno-

|Superman's Pal, Jimmy Olsen #92 (April 1966)

|Created by Mr. Nero

|Magnetic attraction

|

|

|

|

|

|

|Scribblenauts Unmasked Cambridge Dictionary defines the figurative use as "something that hurts or damages a person or thing that usually seems strong", Dictionary.com defines it as "something that a person or thing cannot defend against or defeat", and Collins defines it informally as "something that renders a person or thing helpless". Michael Pedler writes that "Superman's Kryptonite remains a kind of pop-cultural shorthand" for an "Achilles' heel".

Brian Holmes, Jeremy Bolen and Brian Kirkbride use the word in a different scholarly context in "Born Secret (Cash for Kryptonite): A field guide to the Anthropocene mode of production", an article on art, technology and political ecology that examines the Tennessee Valley, hydroelectric modernization and the Manhattan Project. The title uses the term "kryptonite" to represent hidden vulnerability, exposure and destructive technological power.

The term has seen usage in popular media. In music, kryptonite is often used metaphorically for dependence, loyalty or personal susceptibility. A prominent example is 3 Doors Down's 2000 single "Kryptonite"; songwriter Brad Arnold described the song as being "about friendship" and asking, "Will you just be there for me?" In wider film, television, sports and cultural commentary, the word is used as shorthand for a character flaw, a team's weakness or a system's point of failure; The Atlantic describes figurative use as "a moral weakness" or "a character flaw". The title of Craig Colasanti's 2018 indie crime thriller Kryptonights about an NYPD detective uses the fictional substance as a play on words.

References

  • The Superman Homepage's section on kryptonite
  • Howstuffworks.com: "How Kryptonite Works"