Smallville Wiki

Green Kryptonite, which is commonly found in Smallville.

"Their home is their only poison."
— Lionel Luthor, under a Crystal's influence. Arrival

Green Kryptonite is the most common form of Kryptonite, a radioactive ground mineral that made up most of the planet Krypton's structure, including its core.[1] Clark told Kara that Kryptonite was "radioactive pieces of our home world" that landed on Earth in October 1989 during a spectacular and destructive meteor shower which struck Smallville and concealed the arrival of the baby Kal-El.

Early History

The meteor shower that brought massive amounts of Kryptonite.

Kryptonite was also found on Earth in Asia, long before Krypton's destruction, suggesting it might be a naturally occurring radioactive element from Krypton or that someone brought it to Earth.

The Kawatche had a legend about special green stones brought by Naman, which had strange effects on the people. The description of the green stones and their mutagenic effect on the Kawatche matches the profile of Kryptonite.

A meteor rock.

It is unclear how radioactive pieces of Krypton made it to Earth hundreds of years before the explosion of the planet, though the naturally occurring element theory could be correct.

Either way, much more of the mineral arrived with the 1989 and 2005 meteor shower in Smallville. Since then traces of the mineral can be found across the globe, but especially in Smallville where the meteor shower was centered.

Powers and Abilities

Effects on Kryptonians

Green meteor-rocks are commonly found around Smallville.

Green Kryptonite emits a radiation that is extremely toxic to super-powered Kryptonians. The radiation itself first causes symptoms such as nausea, dizziness, pain, and weakness that eventually grow more severe until loss of consciousness occurs.[2] It "boils" Kryptonians blood when exposed directly. (Phoenix) Green Kryptonite is extremely harmful and damaging to anything of Kryptonian-origin (except for Brainiac) and can damage them to the point of corroding, as seen with the Kryptonite key and Clark's ship, and Tess most likely used Green Kryptonite in some way to destroy the Black crystal, which couldn't have been destroyed or damaged by anything earthly, being Kryptonian.

Clark weakened by green Kryptonite.

When a Kryptonian is exposed to the radiation of Green Kryptonite, it breaks down a Kryptonian's invulnerability, allowing outside forces to damage the body. Prolonged exposure or large amounts of Green Kryptonite will ultimately lead to death.[3] It has been noted though that as Clark gets older the effects of Kryptonite seem to affect him a little less.[4]

Kryptonite in relics.

Effects on Bizarro

This type of Kryptonite seems to have healing and energizing properties for Bizarro. When he is exposed to the radiation of it, it greatly increases his physical strength and accelerates his Healing factor as he absorbs the radiation into his body.

Many metahumans with power bestowed upon them from Green Kryptonite can use that power against Clark Kent and other Kryptonians. However, Clark has also shown to be immune to other metahumans' abilities. (See Clark's metahuman vulnerability for specific examples.)

Green Kryptonite can be used to disable the red and gemstone Kryptonite effects.[5]

The effects of Kryptonite on humans are usually irreversible.

Effects on humans

See also: Meteor infection and Kryptonite psychosis

Jodi Melville ingesting a Kryptonite-tainted drink.

Green Kryptonite can be briefly handled and sometimes even ingested by humans after being manufactured without immediate danger. Humans don't experience the weakness and incapacitation suffered by Kryptonians. However, long-term exposure to the green meteor rocks of Smallville has been shown to have significant effects on humans. Also, different types of Kryptonite have different effects.[6]

Green Kryptonite affecting a human.

Many of Smallville's residents (or even visitors) suffer from meteor rock infection. It often causes mutations, personality changes, psychosis, or a variety of other adverse reactions. The majority of Kryptonite-infected individuals display phenomenal metahuman powers, but most are also psychotic versions of their former selves, with personality traits or desires often enhanced to the point of obsession.

Clark uses Green kryptonite and electricity to reverse the incomplete transfer of his powers to Lana.

A Green Kryptonite, when in contact with a strong electric current (such as lightning), sometimes has the ability to transfer Clark's powers to humans and vice versa.[7]

Meteor rock infection also has been shown to have adverse physical effects:

  • Earl Jenkins and Steven Hamilton developed a neurological disease from meteor rock exposure which included uncontrollable tremors and psychotic behavior. Both eventually died from these ailments. (Jitters, Duplicity, Chloe Chronicles)
  • Moira Sullivan's meteor rock infection rendered her unresponsive and catatonic for several years. (Progeny)
  • Lex Luthor was rendered bald due to his exposure to meteor rock, which presumably increased his white blood cell count.
  • Wade Mahaney became intangible after injecting Kryptonite as a tattoo ink. The molecules of his body sped up so rapidly that he could pass through solid objects, but the stress caused his body to start breaking down. (Kinetic)
  • The clone generated from Emily Dinsmore grew rapidly due to Green Kryptonite. (Accelerate, Forsaken)
  • Buffy Sanders contracted a form of rabies that had been mutated into a vampiric disease from meteor rock exposure. (Thirst)

Green Kryptonite.

It should be noted that although Lana Lang wore a meteor rock necklace for several years, she did not experience any health problems related to meteor rock infection.

Chloe Sullivan also had a Kryptonite-filled heart for nearly 20 years and suffered no ill effects. Lex also wore a Kryptonite ring and was exposed to Kryptonite objects in his vault, but also so far has been unaffected.

A few infected individuals seem to escape psychosis. An example is Chloe Sullivan. So far, her power of empathic healing has not seemed to significantly change her personality. This is in stark contrast to her exposure to Kryptonite gas, which significantly changed her personality.

As Fuel

Green Kryptonite is highly combustible. When Pete was street racing, he used a nitrous system that used Kryptonite to give him a serious boost of speed.

Effects on Fruit & Vegetables

In 2005, Luthorcorp experimented by irradiating vegetables with Green Kryptonite to make corn "grow twice as fast" and improve the quality of apples. But it had adverse negative affects,[8] unlike Blue kryptonite which can positively enrich organic life to unnatural levels.[9]


Green Kryptonite in a lead box.

The effects of Kryptonite on Kryptonians can be shielded or blocked with lead.[10] Also, some Kryptonian technology can neutralize the effects of Kryptonite. LuthorCorp was able to develop a technology to absorb the radiation of Kryptonite.

Heat vision destroying Kryptonite.

Normally, heating Green Kryptonite results in the creation of black kryptonite. However, Kryptonians are shown to be able to destroy Green Kryptonite with heat vision without changing it into its black variant.

In the Comics

Kryptonite types on the comics.

The material is usually shown as having been created from the remains of Superman's native planet of Krypton, and generally has detrimental effects on Superman and other Kryptonians. The name "Kryptonite" covers a variety of forms of the substance, but usually refers to the most common "green" form. Kryptonite is one of the few things that can kill Superman.

Despite the matching name, it was never suggested that the element Kryptonite had any significance to the name of the planet Krypton. Under standard chemical naming procedures, the -ite suffix of Kryptonite would denote an oxyanion of the element Kryptonite. However, Krypton is a noble gas that forms compounds only with great difficulty, and such an oxyanion is not known.

Green Kryptonite in the comics.

Green Kryptonite is the most common form of Kryptonite. It exists primarily as a metallic ore, but can also be found in crystalline forms. The most debilitating aspect of Green Kryptonite does not stem so much from the unrefined ore itself, but rather from the waves of radiation that it generates. Exposure to Green Kryptonite radiation will greatly weaken a Kryptonian, robbing them of their powers. Prolonged exposure to green Kryptonite proves fatal. Over time, a Kryptonian may develop a slight immunity to the effects of Green Kryptonite, but ultimately, Green Kryptonite radiation will poison the body's cell structure, resulting in death.

Green Kryptonite is also deadly to normal humans, but its effects take longer to fully develop. Lex Luthor once fashioned a small piece of Kryptonite into a gemstone, which he fitted into a ring. After wearing the ring for several months, the radiation produced cancerous growths in his hand, and he was forced to amputate the diseased limb.

Kara Kent AKA Supergirl was locked in a Kryptonite radiated filled ship for 30 years before she started suffering any ill effects from the exposure. Kryptonite is much more deadly to Kryptonians than it is to humans.


Lionel: Their home is their only poison.
Season Five, Arrival

Kara: [T]hose green rocks – they keep weakening me.
Clark: Yeah, trust me – you want to stay away from them. If you're around them too long, they can kill you.
Kara: Kill me? Zor-El told me that the yellow sun would give me abilities beyond my wildest dreams, but he definitely never mentioned any fatal weaknesses.
Clark: It's because he didn't know. The green rocks, they're called Kryptonite – radioactive pieces of our homeworld.
Season Seven, Kara

See also

Kryptonite in Smallville
Types Natural: GreenRedBlueGold kryptonite • Processed: BlackSilverGemstoneClear kryptonite
Effects Meteor infectionPsychosisMeteor freaks
Objects BulletCageHandcuffsHeartKeyRingNecklaceVictory ring
Other KryptonMeteor showers (1989, 2005) • Lead (box) • Appearances of Green K (usages)


  1. Kara
  2. Clark frequently exhibits these symptoms when exposed. Dizziness and blurred vision were displayed in Phoenix, and he has passed out from it in Commencement and Progeny.
  3. Chloe states that Clark will die if left in Kryptonite-lined tunnels in Traveler.
  4. In Abandoned, Clark was in direct contact with Kryptonite but it should be noted that at first he seemed little affected by it. It seems that Clark can use his other powers while being imprisoned in a Kryptonite cage (Abandoned) .
  5. This can be witnessed clearly in Crimson, Persuasion and Upgrade.
  6. For example a Blue Kryptonite makes humans healthy and purify water, a Green Kryptonite gives humans superpowers. When someone ingests enough Kryptonite they emit the radiation so if someone ingested Red K they would emit that radiation and effect Kryptonians.
  7. Leech, Asylum, Wrath
  8. Onyx
  9. Harvest
  10. Clark learns this in Metamorphosis and keeps a lead box with a piece of Kryptonite in it for emergencies. This formula also works with blue Kryptonite