The element Cavorite had the symbol "CO" which is the same atomic symbol (half-capitalized) used for Cobalt. It was apparently named for the fictional element from H.G. Wells' The First Men in the Moon. Cavorite was supposedly impervious to gravity and could shield other materials from its effects. It was used to shield a craft from the Earth's pull, allowing discoverer Mr. Cavor to travel to the Moon.