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Green Kryptonite, which is commonly found in Smallville.

Kryptonite is a radioactive mineral that made up most of the planet Krypton's structure, including its core.[1] Large amounts of the substance landed on Earth in October 1989 during a spectacular yet destructive meteor shower which struck Smallville and concealed the arrival of the baby Kal-El and his cousin Kara Zor-El.

Since the 1989 meteor shower, Kryptonite are found in the soil of the town in abundance and are known to the residents as "meteor rock." Clark Kent termed the rocks "Kryptonite" after learning of his heritage;[2] since then, that name has been used by those who know his secret.


Natural varieties of Kryptonite appear in crystalline forms of varying sizes, ranging from dust to large chunks in the case of green, red and even blue Kryptonite. Both each of the natural variants and one of the synthetic variants glow a bright color in the presence of Kryptonians or Kryptonian organisms.

Powers and Abilities

Kryptonite is most commonly found in a dark green form, but exists in several varieties designated by color. Under Krypton's red sun, Kryptonite is harmless to Kryptonians but under a yellow sun, or the red sun Zod made out of Earth's yellow sun, different types affects Kryptonians differently, though green, red, blue and gemstone Kryptonite can have dramatic effects on humans as well. Additionally, blue Kryptonite retains its effects under Krypton's red sun enabling Jor-El to de-power the Orb clones with a piece of it.

Natural Kryptonite

There are four forms of Kryptonite that appear to occur naturally:

Image Type Remarks
Smallville112 018.jpg Green Kryptonite It emits a radiation that is extremely toxic to superpowered Kryptonians. The radiation itself first causes symptoms such as nausea, dizziness, pain and weakness that eventually grow more severe until loss of consciousness occurs. Green Kryptonite can also affect humans, causing mutations and psychosis
Red kryptonite.jpg Red Kryptonite It brings out the rebellious and immoral personality of Kryptonians and rids them of most of their inhibitions. The effects of Red Kryptonite are likened to that of being under the influence of too much alcohol, without the loss of physical capability.
Dax-Ur blue k bracelet.jpg Blue Kryptonite It suppresses Kryptonian powers, making them vulnerable like a mortal. It appears to contribute to human health. However, the effects of this kind of Kryptonite disappear by ceasing to be in contact with it.
Svgold1.jpg Gold Kryptonite It can give Kryptonians permanent wounds and strip them of their powers and abilities for good. Prolonged exposure is believed to prove fatal.
Synthetic Kryptonite

There are four additional forms of kryptonite that appear to be processed or synthetic:

Image Type Remarks
401Smallville0766.jpg Black Kryptonite An artificial variant of a Green Kryptonite made when super heated. It has the ability to separate peoples' ego (better qualities) from their id's (darker impulses) on contact.


Smallvilles09e13720pblurayx264sinnersmkv 001014011.jpg Gemstone Kryptonite It is made of white minerals originally found in a quarry in Smallville. It causes Kryptonians to exhibit wish-fulfilling properties and seems to give them temporary powers of persuasion. The effects from the mineral can also affect the infected with it. This type of Kryptonite can be counteracted by Green Kryptonite. (Persuasion)
Splinter862.jpg Silver Kryptonite It is a synthetic form of Kryptonite created by Brainiac that induces paranoia in Kryptonians, such as Clark. (Splinter)
Visage8.jpg Clear Kryptonite It is a Green Kryptonite that has been neutralized. It is harmless to Kryptonians. It first appeared when Lana's necklace got too close to Kal-El's ship, and the ship turned the Kryptonite from a green to a transparent glass-like form. It is unknown if the same effect works on other types of Kryptonite.


Green Kryptonite in a lead box.

The effects of Kryptonite on Kryptonians can be shielded or blocked with lead.[3] Also, some Kryptonian technology can neutralize the effects of Kryptonite. LuthorCorp was able to develop a technology that could absorb Kryptonite radiation.


Kryptonite was named by Clark after he first learned he was a Kryptonian from the now-destroyed planet Krypton. Kryptonite is a name mixed with "Krypton" and "meteorite."

In the Comics

Kryptonite types in the comics.

Kryptonite 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.

The 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 a 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.

A 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-irradiated 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.

In the New 52 universe, Kryptonite originates from Clark Kent's rocket engine core from his rocketship. The core is made entirely of an unshielded and unrefined Kryptonite that can kill or change Superman in some way (an unlimited power source which is lethal to almost everyone), and this man knows that with it he can derive all of the radioactive isotopes, including Red-K, Silver-K, Black-K and Blue-K (which is the most terrible of all).


Martha: If the green meteor rocks affect Clark physically, maybe the red affects him...emotionally.
Season Two, Red

Clark: Mom, you don't think I really meant those things I said about you and Chloe?
Martha: I think there was a grain of truth in all of it. Every time you've been affected by Red Kryptonite, it hasn't changed who you are. It's just stripped away your inhibitions. I think you need to start being more honest about how you feel.
Season Six, Crimson

Kara: I would do it myself, but those green rocks, they keep weakening me.
Clark: And trust me, you want to stay away from them. If you are 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: That's because he didn't know. The green rocks, they are called Kryptonite--radioactive pieces of our homeworld.
Season Seven, Kara

Future Lois: Wait a minute. Oh, no. Kryptonite again?
Clark: Look, I...
Future Lois: (looks into Clark's eyes) Blue? Red? Not green? Please tell me it's not the black. Because that was a disaster.
Season Ten, Homecoming

Clark Luthor: (to Tess) It still bothers you, doesn't it? There's no take-backs when it comes to Gold K. Lex sure knew how to leave an impression, didn't he?
Season Ten, Luthor

Emil: So, I pulled the geological surveys you gave me and Clark's info from the alt-world was right.
Tess: About?
Emil: Well, the surprise at the end of the Kryptonite rainbow, the gold stuff exists.
Tess: What does it do to him?
Emil: Well, drawing on the Veritas journals, Chloe's database and my best calculations, it could take away his powers. For good.
Season Ten, Kent

Zod: Funny isn't it the only thing that can hurt us on their planet is a piece of ours.(While holding a green Kryptonite sword.)
Season Nine, Upgrade

See also


  1. Kara
  2. Visitor
  3. 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.
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)