Kryptonite

Kryptonite is a fictional element from the Superman comic book series.

Before Crisis on Infinite Earths

Before the Superman mythos was redefined by writer John Byrne, the pre-Crisis DC Universe was home to a variety of elements called Kryptonite. Kryptonite was produced from the material of Superman's home planet Krypton, when it was destroyed in an explosion. Kryptonite is usually found in the form of a glowing green rock or metal, but crystalline forms have also made appearances (most notably Jewel Kryptonite, see below) along with different-colored variants such as red kryptonite. These different forms may represent multiple allotropes or isotopes of Kryptonite, or a more exotic variation in composition based on currently unknown particles.

Near the end of the run of the Pre-Crisis Superman, all known Kryptonite on Earth was transmuted into iron, but Kryptonite can be synthetically manufactured by a variety of unknown means and additional material left over from the destruction of Krypton continues to fall from space.

Kryptonite emits a radiation that has an adverse effect on Kryptonian natives such as Superman, though different varieties of kryptonite have different effects. It was assumed for a long time that Kryptonite radiation was harmless to non-Kryptonians, but occasional isolated incidents were reported where it had sporadic effects. It is not known what the half-life of any of Kryptonite's forms is.

The 13 known forms of Kryptonite

• Green Kryptonite - In superpowered Kryptonians, causes immediate physical pain and debilitation and kills within hours. Has no short-term effects on humans or non-superpowered Kryptonians. The most common form of Kryptonite.
• Anti-Kryptonite - Has no effect on superpowered Kryptonians, but has the same effects as green Kryptonite on non-superpowered Kryptonians.
• Red Kryptonite - created from green Kryptonite that passed through a mysterious red-hued cloud en route to Earth. Red Kryptonite inflicts random effects (physical transformations, mostly) on Kryptonians. Each specific chunk of red Kryptonite has the same effect on all Kryptonians, but no two chunks have the same effect as one another. Red Kryptonite effects typically last for 1-2 days, after which the Kryptonian in question is forevermore immune to that specific chunk of Red Kryptonite.
• Gold Kryptonite - removes superpowers from Kryptonians permanently.
• White Kryptonite - kills all plant life, whether Kryptonian or not. Induces decay immediately upon exposure, with a range of about 25 yards.
• Blue Kryptonite - The result of using Professor Potter's "duplicator ray" on some green Kryptonite. Blue Kryptonite kills Bizarros, but has no effect on Kryptonians. (In the Super Friends TV series, Blue Kryptonite is used to reverse the effects of Red Kryptonite on Superman.)
• X-Kryptonite - Created by Supergirl while experimenting with green Kryptonite. It has no effect on Kryptonians, but bestows temporary superpowers on Earth lifeforms, most prominently Supergirl's pet cat (see: Streaky the Supercat).
• Jewel Kryptonite - Jewel Kryptonite amplifies the psychic powers of Phantom Zone residents, allowing them to project illusions into the "real world" or perform mind control. It was made from what was left of a mountain on Krypton called Jewel Mountain.
• Slow Kryptonite - A modified variety of green Kryptonite produced by a Terran scientist that decelerates the speed of nerve impulses, and movements of both Kryptonians and Terrans.
• Silver Kryptonite - A fictional variety of Kryptonite that was used in a hoax perpetrated by Superman's friends in honor of the 25th (silver) anniversary of Superman's arrival on Earth.
• Yellow Kryptonite - Another fictional variety, this one used in a hoax masterminded by Lex Luthor.
• Pink Kryptonite - From an alternate timeline in Supergirl, this variety of Kryptonite turns Kryptonians (apparently) gay. However, this was intended as a joke, not part of normal comics continuity.
• Black Kryptonite - First used in the Smallville TV show. This variety of Kryptonite was used in the episode "Crusade". It is apparently able to separate certain entities from people.

Post-Crisis

After the DC Comicbook universe event known as "Crisis on Infinite Earths" in 1985, the entire Superman mythos underwent a substantial retcon, rewriting Superman as more human and less invulnerable. Among the many changes were the properties of Kryptonite. In the post-Crisis universe, only one form of Kryptonite is naturally occurring: the green variety. It is a mildly radioactive element that was formed in the crust of the planet Krypton as the result of an ancient Kryptonian war. As millennia passed, the radiation from this mineral began to kill Kryptonians; it became known as the green plague. This eventually led to the planet's core becoming unstable, leading to the destruction of Krypton.

Some issues of Superman have indicated the mechanism by which Kryptonite hurts Superman. Superman in some ways is a living solar battery; his cells absorb electromagnetic radiation from yellow stars (like our Sun). Kryptonite's radioactivity interferes with this semi-photosynthetic process, driving the energy out of his cells in a painful fashion. Long term and high-level exposure can be fatal to Superman. Long-term exposure of Kryptonite to human beings is known to have the same effect as exposure to Earth-borne radioactive materials. These effects include cancer. The billionaire industrialist and inventor Lex Luthor discovered this inadvertently after acquiring a ring with a green Kryptonite fragment set in it to provide protection against Superman.

It is speculated that Kryptonite may be located in a hypothetical "island of stability" high on the periodic table, beyond the currently known unstable elements, in the vicinity of atomic number 150. The transmutation of Earth's Kryptonite could be explained by the acceleration of its natural atomic decay under this theory.

Two Post-Crisis stories have featured artificially created Red Kryptonite. The first kind was a Kryptonite-like, but non-radioactive rock that seemingly stripped Superman of his powers (although the source was actually Mr. Mxyzptlk's magic) in the story "Krisis of the Krimson Kryptonite".

The second, in the JLA story "Tower of Babel", was created by Batman as a way of stoping Superman without killing him, should this prove necessary. It is a "relatively stable" isotope of Kryptonite, which disrupts Kryptonian cells in an unpredictable way. In the story, it turned Superman's skin transparent, resulting in his "solar batteries" overloading.

Depiction in other media

Superman's first encounter with kryptonite did not take place in his comic. It was actually introduced in 1943 on the Superman radio series. The episode in which it first briefly appeared now exists only as a script, but the substance played a part in at least one major plotline during the course of the program. It was not until 1949 that the comic book writers incorporated it into their stories, as a convenient danger to Superman, to make his adventures more exciting. Jerry Siegel did write a story in 1940 that involved a piece of Krypton, referred to as "K-Metal," which robbed Superman of his strength while giving Earthlings super powers, but it was never published.

Most depictions of kryptonite in the various films and TV series of Superman have largely been limited to the Green varieties with occasional appearances of Red and Blue.

Kryptonite was featured in Superman: The Movie. A form of artificial Kryptonite that turned Superman evil appeared in Superman III.

In the television series Smallville, the show expands on the concept of the substance being harmful to humans. On the show, not only is green Kryptonite (commonly known as "meteor rock") harmful to Clark Kent, but it can produce bizarre changes in humans, typically turning them into powerful mutant menaces that Clark must oppose. These changes seem to be linked to the condition in which the subject was exposed to kryptonite. Groups of people have been shown to acquire the same powers from Kryptonite by exposing themselves to it in the same manner. (Some fans have referred to Smallville Kryptonite as "Red Earthite").

The red variety of Kryptonite has also been shown in Smallville. Its effect on Clark Kent is to suppress all inhibitions. His friend Pete Ross summed up the effects of Kryptonite as "green means stop, red means go."

In The New Adventures of Superman, a scientist created hybrid Kryptonite, which has no effect on Kryptonians but hurts humans. Red Kryptonite also featured in the series. In one episode it made Superman apathetic; in another it transferred his powers to Lois.

Afternotes

Several sources have calculated the total mass of the planet Krypton based on the estimated mass of Kryptonite that fell to Earth, the assumption that the initial explosive distribution of pieces of Krypton was isotropic, and determinations of the mean distance between Krypton and Earth derived from certain passages in the Essene New Testament. The results are confusing at best, as the estimated mass of Krypton is 10⁷ times the mass of our own sun, so a black hole was inevitable and the existence of corporeal life on the planet beforehand is questionable in the extreme. One possible explanation that has been proposed by fans is that Kal-El's own spacecraft's propulsion system somehow caused a disproportionate amount of debris from Krypton to follow it to Earth. Further work on this topic continues.

Disambiguation

• The Kryptonite lock is a famous brand of bicycle lock.
• "Kryptonite" is the title of a song by 3 Doors Down on their album The Better Life.