Kryptonite is a unique, naturally-occurring crystal from the planet Krypton in the Ben 10 Universe.
Occurrence
Kryptonite naturally occurs in the Darklands regions of Krypton, and also makes up part of the mineral composition of the Rrejjoe species.
Usage
Kryptonite is a highly sought-after material due to its inherent ability to absorb solar energy. The diet of the Rrejjoe depends entirely on pure kryptonite crystals, whereas Kryptonians use it to power their city clusters across the surface of Krypton.