Promethium is a chemical element with symbol Pm and atomic number 61. Promethium may also refer to: Fictional entities Promethium, a fictional petroleum-based fossil fuel as well as a refined napalm-like substance in Warhammer 40,000 Promethium, the name of the Mechanic Empire's queen in the fictional universe of Leiji Matsumoto Promethium (Marvel Comics), a fictional, magical metal in the stories published by Marvel Comics See also Prometheum, a genus of plants in the family Crassulaceae Pm (disambiguation) Proscenium, the concept of space in live theater Prometrium, a brand name of the drug progesterone