Many forms of Kryptonite have been created for various comic books, but how many types of Kryptonite have made their way into the Arrowverse? This question was raised in recent weeks, when an episode of Superman and Lois revealed that Kryptonite meteors rained down upon the Earth for a week after the arrival of the rocket carrying an infant Kal-El from Krypton. Potentially that means there could be more forms of Kryptonite in the Arrowverse than have previously been chronicled.
The basic idea for Kryptonite was first conceived by Superman co-creator Jerry Seigel, who wrote a story in 1940, “The K-Metal from Krypton,” centered around a mineral from Krypton that drained Superman of his strength while giving superpowers to Earthlings. While the story was rejected and never published (due to it ending with Superman revealing his secret identity to Lois Lane) a similar idea was later introduced in the Adventures of Superman radio program. It was here that this weakening mineral was introduced under the name Kryptonite, in an episode titled “The Meteor from Krypton,” in June 1943. Kryptonite was officially introduced into the comics six years later, in November 1949, in Superman #61.
Since that time, Kryptonite has become synonymous with secret weaknesses in American pop culture, similar to the terms Achilles’ Heel or silver bullet. While the exact details have differed from story to story and adaptation to adaptation, Kryptonite is so famous that even people who don’t read comics are aware of what it is and how it sickens Superman. And yet, much like Superman himself, Kryptonite has evolved over the past eight decades, with other forms of Kryptonite having come into existence that do far more than just making a Kryptonian mortal. Here’s a rundown of each form of Kryptonite that exists in the Arrowverse, and their effects.
Green Kryptonite
Green Kryptonite is the most common form of Kryptonite and the type most people envision when they hear the word. The radiation of Green Kryptonite weakens Kryptonians, causing symptoms including nausea, dizziness, vertigo and fatigue. When injected into a Kryptonian, Green Kryptonite causes their veins to glow green and pop up on the skin. Green Kryptonite can be used as a sedative in small doses, but prolonged exposure is lethal and feels, according to Supergirl, like having “nails in your blood.”
Weapons made of Green Kryptonite can cut or pierce a Kryptonian’s skin. However, while the pain caused by physical contact with Green Kryptonite is intense, it does not deprive a Kryptonian of the powers, although it might make them vulnerable to ordinary weapons. This was shown in one episode of Superman and Lois, where Superman maintained the focus to repress his heat vision while pulling Green Kryptonite shards from his shoulder, before safely burning the Kryptonite with a controlled blast.
While Green Kryptonite radiation is seemingly non-lethal to humans, Green Kryptonite is toxic when introduced into the human body. The second Batwoman, Ryan Wilder, discovered this the hard way, after she was shot with a shard of Kryptonite by the villain Hush. While the wound was superficial, Ryan slowly began to develop symptoms similar to Kryptonite poisoning in a Kryptonian, which could only be cured by an elixir made from the rare Desert Rose of Coryana.
Blue Kryptonite
In the comics, Blue Kryptonite was not harmful to Kryptonians, but it was lethal to the inhabitants of Bizarro World, either weakening them physically or forcing them to think rationally, which was also painful for them. In the Arrowverse, Alex Danvers created Blue Kryptonite by reversing the ionic charge of Green Kryptonite. It had no effect on Supergirl, but did act as a sedative on the degenerated Supergirl clone created by Maxwell Lord, in the Supergirl season 1 episode “Bizarro .” Curiously, the clone was made stronger yet more unstable after being exposed to Green Kryptonite.
Red Kryptonite
In the comics, Red Kryptonite was the most unstable form of Kryptonite, with each piece causing a unique but temporary effect. These included transforming Kryptonians into dragons or causing excessive hair growth or rapid aging. In the Arrowverse, Maxwell Lord created Red Kryptonite in the Supergirl season 1 episode “Falling,” hoping to fashion a non-lethal form of Kryptonite that could weaken Kryptonians without killing them. Instead of weakening their bodies, the Red Kryptonite weakened Kryptonians’ minds, slowly causing them to lose their inhibitions before finally destroying all sense of morality or restraint. Thankfully, Lord was also able to synthesize a cure for Red Kryptonite poisoning after accidentally creating his worst nightmare; a berserk Supergirl.
Silver Kryptonite
Silver Kryptonite first appeared in July 1963, in Superman’s Pal Jimmy Olsen #70, where it was a simple prop Jimmy had created to celebrate Superman’s 25th (or Silver) Anniversary. Later stories introduced a true Silver Kryptonite, which was renowned both for mystic properties that strengthened magical amulets forged from it and for having an effect on Kryptonians similar to that of marijuana on humans. The Arrowverse version of Silver Kryptonite was something else entirely, causing Kryptonians who were exposed to it to hallucinate their worst fears made real. Queen Rhea of Daxam used a piece of Silver Kryptonite to cause Superman to hallucinate that Supergirl was a resurrected General Zod, in the Supergirl season 2 episode “Nevertheless, She Persisted.”
Black Kryptonite
Also known as Harun-El, Black Kryptonite was a key component of the plot of Supergirl seasons 3 and 4. On Krypton and in the Kryptonian colony of Argo City, Black Kryptonite was harmless to Kryptonians and used as a power source to generate the dome and artificial gravity that made Argo City possible. Some unknown quantity on Earth made it lethal, however, with Black Kryptonite radiation on Earth causing Kryptonians great pain as their powers became unstable. The touch of Black Kryptonite could split a Kryptonian into two different beings; a process which allowed Lena Luthor to separate the Wordkiller Reign from her human persona, Samantha Arias. This was the same effect Black Kryptonite had in the comics and it also led to the accidental creation of the Supergirl clone known as the Red Daughter.
Black Kryptonite’s effect on humans was radically different. Lena Luthor attempted to use Black Kryptonite to fashion a miracle cure-all for cancer and other seemingly incurable conditions. In the process, she accidentally discovered a way to temporarily give humans Kryptonian powers, though the process caused their bodies to deteriorate quickly. Both Agent Liberty and Lex Luthor used Black Kryptonite to empower themselves, nearly dying in the process.
Synthetic Kryptonite
Pre-Crisis, all of the Kryptonite on Earth-38 not hidden away by Lex Luthor was destroyed by Superman and the DEO. This led several parties to create Synthetic Kryptonite, which acted much the same as Green Kryptonite. However, some forms of Synthetic Kryptonite, such as those created by Project Cadmus to power their Metallo soldiers, were much less stable than Green Kryptonite and prone to exploding. The Oliver Queen of Earth-1 was somehow able to create a stable form of Synthetic Kryptonite, despite their being no Kryptonians on his Earth. This proved handy during the battle with an evil Supergirl during the cosmic event that became known as Crisis on Earth-X.
Post-Crisis, Lex Luthor armed the DEO with weapons and armor powered by Synthetic Kryptonite. General Sam Lane also developed Project 7734, creating weapons that made use of Synthetic Kryptonite in case he was ever forced to face a Superman who had been mind-controlled or gone rogue. These included a Kryptonite-based smoke-bomb, which it was hoped would temporarily weaken Kryptonians and make them vulnerable to traditional weapons. Unfortunately, while the Kryptonite gas weakened Superman enough for him to be bruised by regular bullets, it had an unexpected and far more devastating side effect on Jordan Kent, whose physical resistance was lowered by the Synthetic Kryptonite energy his father was unwittingly radiating. This triggered a severe cold in Jordan, which caused him to unleash torrents of Ice Breath whenever he sneezed.
X-Kryptonite
In the comics, X-Kryptonite was a form of Kryptonite that Supergirl created by accident while trying to create a cure for Kryptonite poisoning. Instead of becoming inert, the X-Kryptonite began to radiate an energy that gave Kara Danvers’ pet cat Streaky the powers of a Kryptonian. The Arrowverse version of X-Kryptonite introduced on Superman and Lois is somewhat different, being a naturally occurring element and, according to John Henry Irons, the rarest form of Kryptonite on his home Earth. It remains to be seen just how rare it is on Earth-Prime in the Arrowverse, but neither Superman nor Lois Lane had ever heard of it before billionaire Morgan Edge bought the abandoned Shuster Mines of Smallville in order to acquire it. This new Kryptonite apparently has the ability to give humans Kryptonian powers and may also enable Kryptonian consciousnesses to take over human bodies.
