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 K-Metal: A prototype Kryptonite from the famous unpublished Golden Age Superman story by Jerry Siegel and Joe Shuster called "The K-Metal from Krypton!".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.
1. Green Kryptonite: Green kryptonite, the only variety potentially fatal to Superman, 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 Superman of his super-powers were he ever to be exposed to its radiations.(TGSB)
4. Blue Kryptonite: Blue kryptonite is toxic only to Bizarro creatures.(TGSB)
5. White Kryptonite: White kryptonite is harmful only to plant life.(TGSB)
6. Jewel Kryptonite: 1st appeared in Act 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 its Superpowers.
8. Red-Green Kryptonite: Red-Green Kryptonite 1st appeared in the story "The Menace of Red-Green Kryptonite!" in Act No. 275.
9. Anti-Kryptonite: A freak type of Kryptonite which affects only non-super Kryptonians.
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
11. Kryptonite-Plus: 1st appeared in Act #350."a super-powerful isotope that will finish off [Kryptonians] in minutes".
12. Magno-Kryptonite: 1st appeared in SPJO No. 92. Created by Truff, from the planet Pyron. "It [clings] with unbreakable force to anything that comes from Krypton".
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.
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.
Whenever the word kryptonite appears in this encyclopedia without a specific color designation, it is green kryptonite, the most common variety, that is being referred to. (See Superman [ section 7.1, kryptonite ].)