The term used to designate any surviving fragment of the
exploded planet Krypton, home world of Superman.
There are five distinct varieties of kryptonite (green, red, gold,
blue, and white), the first three of which are toxic to
Superman.
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.
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.
Gold kryptonite would permanently rob Superman of his super-powers
were he ever to be exposed to its radiations.
These three varieties of kryptonite are similarly hazardous to
Supergirl, Krypto the Superdog, and all other surviving natives of
Krypton.
Blue kryptonite is toxic only to Bizarro creatures. White
kryptonite is harmful only to plant life. Whenever the word
kryptonite appears in this encyclopaedia without a specific color
designation, it is green kryptonite, the most common variety, that
is being referred to.
