Rhorium is a radioactive element in the periodic table found in Arcanine Royale's universe PokéEarth. It is next to none known to man in unstability, and thus when multiple asteroids containing rhorium struck the earth during its first days when Homo aurorus was establishing a hunter-gatherer civilization, these Aurorans were given extraordinary psychic powers.

Rhorium is a pink metallic element with a silver sheen. Rhorium was not originally natural to the world of PokéEarth, and was only brought to the planet by asteroids of unknown origin or purpose containing large deposits of the subtance. These asteroids brought the only three variants or Rhorium ever to have been on earth. Rhorium's chemical symbol is Ro and is situated in the section of the Periodic Table called Non-Earth metals.