Inertron


Inertron is a fictional metallic chemical substance found in the DC Comics Legion of Super-Heroes universe. It is the hardest, densest substance in the DC universe, and is often used by the Legion of Super-Heroes in the 30th century. The first mention of inertron was in Adventure Comics #336.
Inertron is frequently described as indestructible and impenetrable; however, this only applies to regular humans, lesser superhumans and 30th century known technology, as, on some occasions, Superboy and Mon-El could break an inertron container by using all their strength. In Adventure Comics #370, though, a triple steel layer inertron-sealed prison was described as too tough for Superboy or Mon-El to break through. Matter Eater Lad has been shown to be able to eat it, however. Karate Kid has broken shackles made of inertron one time. In Superboy and the Legion #245, Element Lad pointed out that inertron was an artificial element, which meant it was still an element, and he thus was able to change it to helium.

History

The earliest known mention of inertron was in the August 1928 pulp magazine Amazing Stories, in the first Buck Rogers story, entitled Armageddon 2419 A.D., by Philip Francis Nowlan. Nowlan's inertron was similar to that used in the DC universe, in that it was difficult to obtain and virtually indestructible. Nowlan's inertron was also a perfect gravity shield so that any material above it would be weightless, a characteristic similar to H. G. Wells' cavorite.
According to Armageddon 2419 A.D.:

Other DC Comics fictitious metals