Kryptonite was a "xenomineral" compound that was created from various elements on the Periodic Table. Despite the name, it did not contain the Periodic Element Krypton. It was known as being one of the few weaknesses of Superman, as the material acted as poison to the Kryptonian people. It managed to affect their DNA and quickly kill them, though a relatively large dose was required for this, whereas small doses could weaken them and very small doses did nothing.
- The most famous use has always been the ability to poison a Kryptonian.
- It, if charged correctly, can supercharge humans, but they are left with a craving for more radiation.
- Used to kill the Brother Eye assimilated Superman by Tim Drake.