Kryptonite. The one substance that can kill Superman. Like Jimmy Olson, kryptonite was first featured in the 1940s Superman radio show. Since then, it’s become a recognized staple of the Superman mythos.
But it isn’t always green. And it doesn’t always prove fatal to Superman.
Kryptonite is one of those Silver Age concepts that came about from time to time that was mostly just there because writers and artists of that era may not have known much about science, but they probably knew their juvenile readers didn’t either. As such, strange and weird stuff that would never work in real life, even moreso than the regular premises of these characters, happened on a routine basis. And sometimes those things didn’t get any weirder than a superhero’s weakness. Green Lantern was useless against a primary color. The Martian Manhunter was rendered helpless in the presence of a common chemical reaction. Thor had to come into physical contact with his hammer within 60 seconds to keep his power, and Aquaman had to get hit with some kind of water once an hour. Superman, of course, had kryptonite, the radioactive remnants of the planet Krypton. Used by a wide variety of Superman foes like Metallo and Lex Luthor, for a rare substance there sure was a lot of it. Later writers tried to remove that weakness from time to time, but that never lasts long.
But that same Silver Age general zaniness meant there were lots of different kinds of kryptonite floating around. Many times these new forms were mash-ups of old forms, but here are a few of them that have appeared in one form or another over the years.
Do I need to explain this one? I think I already have.
Red kryptonite in classic Silver Age stories temporarily mutated Superman into something for a period of roughly 24 hours. What that something was would be different any time, like he might become a giant ant or grow an extra eye outside the back of his head, or just turn into King Kong as seen above.
Red kryptonite has been used for other purposes. On various CW shows, it might turn Superman evil or at least cause him to loose his inhibitions.
That’s more or less what happened in this clip here:
Gold kryptonite won’t kill a kryptonian. It will just permanently rob them of their powers.
That might be a problem.
Blue kryptonite is harmless to Superman. That stuff only works on Bizarro.
It’s probably worth noting that Metallo at one point was being powered by a rotating cylinder of green, red, gold, and blue kryptonite.
White kryptonite doesn’t hurt Superman or Bizarro. It just kills any and all plant life in the vicinity.
So, really, that’s Swamp Thing’s weakness.
This one here is one of those obvious Silver Age things. Krypton used to send its criminals to the Phantom Zone, where the residents were, well, phantoms. Jewel kryptonite somehow enhanced their psychic abilities to cause illusions or mind control in the solid world.
Man, that name is terrible.
Anyway, slow kryptonite did to regular humans what green kryptonite did to Superman.
Here’s a fun one.
Classic “black kryptonite” would split kryptonians into two beings, one good and one evil.
But Grant Morrison used a variation of that in his All-Star Superman. In that one, Superman was exposed to the substance and turned temporarily the opposite of his usual self. That forced Jimmy Olson to turn himself temporarily into Doomsday to stop him, but fortunately Opposite Superman is also a coward. Both characters reverted to normal after a period.
Orange kryptonite was from some younger readers titles and gave temporary superpowers to animals.
Aren’t humans animals? Try not to think that far ahead.
OK, this one was a joke from an issue of writer Peter David’s Supergirl run. What did it do? It temporarily turned Superman gay.
I think that’s enough kryptonite for one day…