The term used to designate any surviving fragment of the exploded planet Krypton, home world of Superman. These varieties of kryptonite are similarly hazardous to Supergirl, Krypto the Superdog, Beppo the Supermonkey, and all other surviving natives of Krypton, unless otherwise noted. (edited and modified from TGSB)
Full list of every type of Kryptonite that has appeared in the chronicles is as follows:
0. K-Metal: A prototype Kryptonite from the famous unpublished Golden Age Superman story by Jerry Siegel and Joe Shuster called "The K-Metal from Krypton!". It has the same weakening effect on Kryptonians as Green Kryptonite, with the additional effect of temporarily granting tremendous strength and possibly other super-powers to normal non-powered people. Part of this idea was used for X-Kryptonite in Superman Family No. 203
1. Green Kryptonite: Green Kryptonite, is fatal to superpowered Kryptonians but harmless to non-superpowered Kryptonians, It induces lassitude and inertia followed by death if not removed in time from Superman's presence. (TGSB)
2. Red Kryptonite: Red Kryptonite inflicts bizarre and unpredictable—albeit temporary and nonfatal—symptoms, as when it divides Superman into twins or transforms him into an infant or a giant ant.(TGSB) It's effects last only 48 hours and is never repeated on the same Kryptonian again.
3. Gold Kryptonite: Gold Kryptonite would permanently rob a Kryptonian of his super-powers were he ever to be exposed to its radiations. Phantom Zone escapee Quex-Ul suffered this effect (S No. 157), as did a Lex Luthor-created Superman clone (Act No. 500).(TGSB)
5. White Kryptonite: White Kryptonite is harmful only to plant life, though it can also affect some vareties of microbe.(TGSB)
6. Jewel Kryptonite: First appeared in Action Comics No. 310. Created by Jax-Ur of the Phantom Zone. "That chunk of Jewel K in orbit magnifies our mental commands and converts them into energy beams which detonate any explosive material we desire."
7. X-Kryptonite: Accidentally created by Supergirl, it gives Streaky the Supercat powers beyond those of mere mortal cats. It is revealed in Superman Family No. 203 that X-Kryptonite can weaken superpowered Kryptonians as well.
8. Red-Green Kryptonite: Red-Green Kryptonite first appeared in the story "The Menace of Red-Green Kryptonite!" in Act No. 275.
9. Anti-Kryptonite: A type of Kryptonite which affects only non-superpowered Kryptonians. Initially created to explain a discrepancy in the origin story of Supergirl (namely how the non-superpowered Krypton survivors in Argo City could be affected by lethal Kryptonite radiation).
10. Slow Kryptonite: Created by Metallo. It is "able to slow down the rate of particle emissions enough to affect humans as it does Kryptonians." (B&B No. 175) Although the effect on Batman was agonizing and impressive, the effect (if any) on Kryptonians was not documented.
11. Kryptonite-Plus: First appeared in Action Comics No. 350. "a super-powerful isotope that will finish off Kryptonians in minutes".
13. Silver Kryptonite: A fake Kryptonite created by Jimmy Olsen as a hoax for Superman's Silver Anniversary.
14. Yellow Kryptonite: A synthetic Kryptonite created by Lex Luthor as a hoax to mentally torture Superman. Luthor claimed to have a machine capable of creating hovering Kryptonite globes of various colors, including the previously unknown yellow variety. All the globes were in fact fakes, though they managed to successfully fool a Superman robot.
15. False Kryptonite: Created by Supergirl using magic from a wishing well from a piece of Green Kryptonite, it is perfectly harmless.
16. Synthetic Kryptonite: Synthetic versions of Green Kryptonite created in laboratories.
17. Mutated kryptonite: A white card with a Kryptonian symbol on it used by the villain Zo-Mar was made from an unnamed form of mutated kryptonite that robbed any Kryptonian of his powers when he was very near it, but which was not otherwise harmful and had no permanent effect. (DCCP No. 84).
18. Black Kryptonite: Presented to Martha Kent by Dr. Bridgette Crosby (Margot Kidder) in Smallville episode 4.1, "Crusade", black kryptonite split Clark into two personalities, the heroic Clark Kent and his rebellious alter-ego, Kal-El. This split resulted in a battle between Clark and Kal-El, where Clark eventually emerged victorious.
Whenever the word Kryptonite appears in this encyclopedia without a specific color designation, by default it will be Green Kryptonite, the most common variety. (See Superman [ section 7.1, kryptonite ].)