Andrés Manuel del Río y Fernández was a Spanish scientist, naturalist and engineer, nationalized Mexican, who discovered compounds of vanadium in 1801. He proposed that the element be given the name panchromium, or later, erythronium, but his discovery was not credited at the time, and his names were not used.

Vanadium is a chemical element; it has symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) somewhat stabilizes the free metal against further oxidation.