In its best-known form, it is a green, crystalline material originating from Superman's home world of Krypton that emits a unique, poisonous radiation that can weaken and even kill Kryptonians. Kryptonite radiation can emit through any element except lead. Thus, Superman has a special lead suit to protect himself from the radiation. There are other varieties of Kryptonite, such as red and gold Kryptonite, which have different but still generally negative effects. ``
