Kryptonite
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 Kryptonians. Kryptonite radiation can be transmitted through any element except lead. There are other varieties of kryptonite, such as red 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 being able to project rays of kryptonite radiation from his eyes after being altered by simultaneous exposure to kryptonite and uranium. Due to Superman's popularity, kryptonite has become a byword for an extraordinary exploitable weakness, synonymous with "Achilles' heel".
History

An unpublished 1940 story titled "The K-Metal from Krypton", written by Superman creator Jerry Siegel, featured a prototype of kryptonite.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 give Superman's voice actor Bud Collyer 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. On the other hand, Hayde might have mistaken 1945's "The Meteor of Kryptonite" for 1943's "The Meteor from Krypton", as Superman was exposed in the former but not in the latter.
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, which places Krypton in a distant solar system, 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). Editor Dorothy Woolfolk stated in an interview with Florida Today in August 1993 that she felt Superman's invulnerability was "boring".
Long said to be an element in the Golden, Silver, and Bronze Age comics, Kryptonite is depicted as a compound in post-Crisis continuity.
Forms, effects, and other media
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.

In popular culture
Music
- "Kryptonite" by 3 Doors Down (2000).
- "Party Up (Up in Here)" by DMX (2000).
- "Kryptonite (I'm on It)" by rap group Purple Ribbon All-Stars (2006).
- "Kryptonite" By Mario ft. Rich Boy from his third studio album Go.
- "Fashion Is My Kryptonite" by Bella Thorne and Zendaya (2012).
- "Ready or Not" by Bridgit Mendler (2012).
- "Shut Up and Dance" by Walk the Moon (2014).
- "Get Your Cape On" by Jordyn Kane (2015).
- Pocket Full of Kryptonite, a 1991 album by Spin Doctors. The album's title is drawn from a line in the song "Jimmy Olsen's Blues", which is featured on the album.
- In the title track for his album Ten Feet Tall and Bulletproof, Travis Tritt sings about picking a fight when he feels like Superman "only to find my opponent is holding kryptonite".
- The 2000 song, "Superman (It's Not Easy)" by "Five for Fighting" mentions kryptonite: "...digging for kryptonite on this one way street".
- The Genesis song "The Carpet Crawlers" mentions kryptonite: "Mild-mannered Supermen are held in kryptonite...".
- "There's a Moon in the Sky" by The B-52's mentions kryptonite: "you get a mouth, a mouthful of red kryptonite".
- "Jam on It" by Newcleus features a "battle" between the band and Superman, and they "rock his butt with a 12-inch cut called disco kryptonite".
- "One Thing" by One Direction mentions kryptonite: "you're my kryptonite".
- "Pineapple Kryptonite" by ATARASHII GAKKO!
- "Kryptonita", a 1991 album by Miguel Mateos.