As arguably DC Comics’ strongest hero, Superman is practically invulnerable to most conventional forms of attack. But if there’s one thing to which the Man of Steel and his fellow Kryptonians are vulnerable, it’s Kryptonite.

Though its emerald incarnation is most iconic, Kryptonite comes in all shapes and colors with varying forms of radiation that lead to similarly varying effects on Kal-El and his ilk. And unfortunately for Superman, more than a few variants of Kryptonite are even more worrisome than the kind he already knows and hates.

10 Yellow Kryptonite

First Appearance: Superman Family Adventures #2 by Art Baltazar & Franco Aureliani

One of the more recent additions to the Kryptonite catalogue, Yellow K seems to harbor some latent time travel effects. While the mineral had once seemed to be merely a ruse of Lex Luthor’s to vex the Man of Steel, the real thing first appeared as a genuine Kryptonite variant in the whimsical Superman Family Adventures series, though its canon effects remained unknown for years until Superman #9 by Joshua Williamson, Bruno Redondo, and Adriano Lucas.

Using the yellow shard on his Krytponite gauntlet to disrupt the abilities of the ghostly Marilyn Moonlight, the mad scientist Graft, an old foe of Lex Luthor’s, wound up sending the Man of Steel and his spectral companion back to the Wild West. Whether this occurrence stemmed solely from the Kryptonite itself or rather a random reaction remains to be seen, but it’s clearly quite powerful.

9 Slow Kryptonite

First Appearance: The Superman Sourcebook by Steve Crow, Chris Mortika, & John Byrne

An unorthodox variant of the deadly radioactive mineral, Slow Kryptonite is unique totally unique in its energy signature and the accompanying effects. As deadly to ordinary humans as standard Green Kryptonite would be to Superman and his kinsmen, Slow Kryptonite was developed by the fiendish Metallo.

The mineral earned its name thanks to the specific energy rays it generates. While the energy output of traditional Kryptonite is high frequency, or “fast” rays, Slow Kryptonite’s output is substantially lower in frequency, and “slow” enough to synch with and affect human bodies. To this point, the only appearance of Slow K seems to be in The Superman Sourcebook – a Last-Son-of-Krypton-centered guidebook for the DC Heroes Roleplaying Game – but should it ever appear in mainstream continuity, it could spell disaster for the ordinary citizens of Metropolis.

8 Opal Kryptonite

First Appearance: Earth 2 #0 by James Robinson, Tomás Giorello, & Nathan Eyring

Yet another man-made Kryptonite variant, Opal Kryptonite was created by none other than Terry Sloan pf Earth 2 fame. Also called Mister 08, Sloan was a villainous, Machiavellian version of the Golden Age Mister Terrific hellbent on shaping and “saving” the world to suit his own twisted ends. One such scheme involved betraying his fellow heroes, including Earth 2’s Man of Steel, by temporarily driving Superman mad and turning him against Batman and Wonder Woman.

Thankfully, the effects of Opal Kryptonite are only temporary, and even the mineral itself can only produce such harmful effects for a short time before eventually reverting to an ordinary stone. But anything that can turn nigh-unstoppable Kryptonians into rabid beasts is still a major threat that cannot be ignored by the heroes of the DC Universe.

7 Jewel Kryptonite

First Appearance: Action Comics #310 by Leo Dorfman, Curt Swan, and George Klein

Jewel Kryptonite has appeared in a couple of different continuities with differing effects and purposes to boot, but in both incarnations, this specific form of Superman’s greatest weakness is derived from the remnants of Krypton’s legendary Jewel Mountains. Initially, this Jewel Kryptonite was a boon to Kryptonians – just not any heroic ones – as it acted as an amplifier for the low-level psychic capabilities of those imprisoned in the dread Phantom Zone.

Boosting their mental powers to the point that they could impact the main universe, Jewel K was a formidable threat to Superman and his allies pre-Crisis on Infinite Earths. After the multiverse as condensed into one timeline, Jewel K did appear again, this time as a tool for the Injustice League found in an abandoned Brainiac ship with its post-Crisis properties left a mystery.

6 Platinum Kryptonite

First Appearance: Batman Secret Files #1 by Tom King, Mikel Janín, & Jordie Bellaire

A gift from Superman to his World’s Fienst partner, Batman, Platinum Kryptonite hails from an “impossible planet” inside the Phantom Zone. With a single touch, it can permanently bestow the powers and abilities of Superman and his fellow Kryptonians to ordinary humans. Obviously, Batman elected to continue fighting the good fight the same way he always had, but the existence of such a mineral holds major ramifications for the DC Universe. Sure, it’s only found in the harsh recesses of the Phantom Zone, but it’s not like Kryptonian criminals haven’t treated their exile like a revolving door in the past. Should one such criminal manage to escape with any Platinum K in tow, or should Batman’s piece ever fall into the literal wrong hands, it could spell disaster for the world.

5 Silver Kryptonite

First Appearance: Superman’s Pal, Jimmy Olsen #70 by Jerry Siegel & John Forte

Originally appearing as a prank by one Jimmy Olsen in honor of Superman’s silver anniversary, the true effects of genuine Silver Kryptonite have been fairly consistent across its later appearances. In the hit series, Smallville (2001), Silver K is created by Brainiac and exhibits powerful hallucinatory effects on Kryptonian victims.

When it appeared later in post-Crisis DC Comics continuity, it maintained these same properties with a mystical bent that also strips Kryptonians of their inhibitions and causes hunger cravings similar to certain recreational substances commonly used among typical humans. Obviously, any form of Kryptonite is one that Superman should watch out for, but there are other forms of Kryptonite far less mellow than Silver K – at least if Superman encounters it in small and responsible doses.

4 Black Kryptonite

First Appearance: “Crusade.” Smallville Season 4, Episode 1

Debuting in the fourth season of Smallville, Black Kryptonite made its first comics appearance in the pages of Superman/Batman #6 by Jeph Loeb, Ed McGuinness, and Dexter Vines only to become a major plot point in Supergirl #5 again by Loeb with Ian Churchill and Norm Rapmund. One of the more sinister forms of Kryptonite, Black K originally split any Kryptonian victims into two separate beings – one good, and one evil.

Over time, this emphasis on the darker half has continued to be a thread associated with Black Kryptonite as later iterations streamlined the mineral into simply bringing out and exacerbating a Kryptonian's worse self to the point of murderous villainy as opposed to creating an entirely separate being. Regardless, Black Kryptonite is bad news for Superman and anyone else who comes across it, Kryptonian or otherwise.

3 White Kryptonite

First Appearance: Adventure Comics #279 by Otto Binder, Curt Swan, & John Forte

One of the few forms of Kryptonite not inherently harmful to Kal-El and company, White Kryptonite is actually deadly to any and all forms of plant life. Releasing a form of radiation lethal to vegetation, this irradiated ivory material may be the worst nightmare of environmental entities like Swamp Thing, the Floronic Man, and Poison Ivy, but it’s actually proven quite useful to Superman on more than one occasion.

Not only does White Kryptonite kill all vegetation with which it comes into , it is also deadly to any microbes, bacteria, or viruses from seemingly any planet of origin. It’s even been used by Superman to save plague-ridden alien worlds, and it’s also cured Clark Kent himself of the deadly Virus-X in the past – a rare instance of Kryptonite actually benefiting a Kryptonian.

2 Amber Kryptonite

First Appearance: Dark Nights: Death Metal The Last 52: War of the Multiverses by Regine Sawyer, Alitha Martinez, & Mark Morales

A cursed creation of the Dark Multiverse, Amber Kryptonite itself has never made an official appearance, but its illicit effects are well known thanks to an evil version of Superman’s one and only, Lois Lane herself. Hailing from the Dark Multiverse as well, this corrupted Lois gained the abilities of her husband after exposing him to Amber Kryptonite.

This amber alloy immediately absorbed Kal-El’s abilities, killing him in the process and leaving his corpse vulnerable enough that the hyper-powered Lane cut his head off. Amber K’s existence in the main continuity has yet to be confirmed, but it’s not hard to imagine what a substance like this would be worth to the likes of Superman foes like Lex Luthor, Toyman, or anyone else who wants to take a shot at the Man of Steel.

1 Periwinkle Kryptonite

First Appearance: Superman Family Adventures #9 by Art Baltazar & Franco Aureliani

Arguably the most ridiculous form of Kryptonite out there, Periwinkle K is a relatively innocuous version of Superman’s greatest weakness. Unlike the deadly or painful effects of Green or Red Kryptonite, Periwinkle K harmlessly turns Superman’s skin and clothing to the same color from which it gets its name.

Not only does it give Clark a wardrobe change, it also slightly loosens their inhibitions, and in the case of Superman himself, it makes him a charming and excellent dancer. Periwinkle Kryptonite has yet to vex the Kal-El of Earth-0, but with all the other shades of Kryptonite in existence, chances are it just hasn’t made its way to the prime canon yet. But when it does, Periwinkle Kryptonite will be yet another bittersweet reminder of the homeworld of DC Comics’ Superman.