Whatever size they are, they look like rocks with a glaring, deep blue color.
Powers and abilities
Effects on Kryptonians
Blue Kryptonite strips super-powered Kryptonians of all their abilities, making them mortal and, thus, susceptible to damage and pain as with any human. It is possible that the substance does this by turning off the manifestation of genes that allow Kryptonians to process sunlight while in contact with it. This is evident as Clark was stabbed with a blue kryptonite knife when the Book of Rao was activated. This most likely prevented the Book from recognizing him as Kryptonian and exiling him from Earth, unlike the clones. If the DNA of a Kryptonian is irradiated with blue kryptonite, the resultant Kryptonian will have no power under a yellow sun. Instead, they will gain their powers under a red sun. Blue kryptonite can also render a Kryptonian immune to the effects of green kryptonite, whether their DNA is irradiated by it or they are just in physical contact with it.
Effects on Bizarro
Blue Kryptonite magnifies Bizarro's powers to such an insane degree that his body can no longer withstand them, causing him to shake and explode. Brainiac remarked that it causes an exponential power increase which cannot be regulated, comparable to powering a light bulb with a nuclear reactor.
Effects on humans
Blue kryptonite can drastically improve the health of any non-Kryptonian organism, such as livestock, crops, and humans. Continual consumption of blue kryptonite-irradiated water (caused by blue kryptonite landing in a lake) puts humans in a perfect state of health. However, it was also speculated that blue kryptonite also makes them more prone to mental irregularities, such as unquestionably accepting human sacrifice.
Like other forms of kryptonite, blue kryptonite's effects can be counteracted with lead. The effect when DNA is irradiated with blue kryptonite can be counteracted with a super-powered Kryptonian's blood.
- The fact that Blue Kryptonite can kill Bizarro came from the comics, where Blue Kryptonite affects Bizarros the same way Green Kryptonite affects super-powered Kryptonians.