The city of Kandor was still attached to a chunk of the planet Krypton when Superman recovered it. Why didn't it harm Superman like Kryptonite?


In nearly every version of the legend of Superman, the bottle city of Kandor, was stolen by the entity known as Brainiac before the radioactive event which converted the core of Krypton into a highly volatile and explosive material.

Silver Age Brainiac steals the city of Kandor, adding it to his collection.

Silver Age Brainiac steals the city of Kandor, adding it to his collection.

  • Kandor was not on the planet when Krypton exploded and was not exposed to the transformative elements which converted radioactive parts of the planet Krypton into kryptonite. The Kandorians would have no formal knowledge of Kryptonite, its creation or its effects on native Kryptonians under a yellow sun, until they arrive on Earth and meet Kal-El.

  • Rock, metals and debris from Krypton would not normally be radioactive unless they were the standard suite of heavy metals, standard radioactive materials, and transuranic materials found on planets with metallic cores. The basic infrastructure underneath the Kandorian city would be unremarkable rock, nothing more.


According to the wikipedia article on kryptonite:

In virtually all versions of the Superman mythos, kryptonite is described as having formed through a process of nuclear fusion attendant to the explosion which destroyed the planet Krypton. Some accounts describe the fusion process as a result of the planet-destroying explosion, others as the cause of it, but all agree that the majority of the debris of the planet was converted into kryptonite and propelled into interstellar space by the force of the explosion, with some ultimately reaching Earth and becoming a threat to Superman—and other Kryptonians. In Krypton's former location there is a cloud of gas-form Kryptonite that is lethal to all beings, Kryptonian or not.

Which seems to imply that all Kryptonite is made of debris from Krypton, but not all debris of Krypton is Kryptonite. The portion which is still attached to Kandor falls in the later group.


  • Why didn't it harm Superman? It was a portion of normal Krypton rock.
  • Why didn't it turn into Kryptonite? It wasn't close enough to the explosion that destroyed Krypton to be converted.

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