Whatever size they are, they look like rocks with a glaring, deep blue color.
Powers and abilities
Effects on Kryptonians
A Blue Kryptonite strips Kryptonians of all their powers, 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 genes that allow Kryptonians to provess sunlight while in contact with it. This is evident as Clark was stabbed with a Blue K knife when the Book of Rao was activated. This most likely prevented the Book from recognising him as Kryptonian and exiling him from Earth, unlike the clones. If the DNA of a Kryptonian is irridiated 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 K 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
A Blue Kryptonite magnifies Bizarro's powers to such an insane degree that it causes him to shake and explode. Brainiac remarked that it causes an exponential power increase.
Effects on humans
Blue kryptonite can drastically improve the health of anything organic, such with water, crops, and humans. Continual consumption of Blue Kryptonite puts humans in a perfect state of health.
A Blue Kryptonite can be counteracted with lead. The effect when DNA is irradiated with Blue Kryptonite can be counteracted with a 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.