Sequanium was the proposed name for a new element found by the Romanian physicist Horia Hulubei in 1939.[1][2] The name derived from the Latin word Sequana for the river Seine running through Paris where Hulubei worked at that time.

Hulubei thought he had discovered element 93 in a tantalite sample from the French region Haute-Vienne. The element 93 was synthesised in 1940 and named neptunium.[3]


  1. ^ Fontani, Marco (2005-09-10). "The Twilight of the Naturally-Occurring Elements: Moldavium (Ml), Sequanium (Sq) and Dor (Do)". International Conference on the History of Chemistry. Lisbon. pp. 1–8. Archived from the original on 2006-02-24. Retrieved 2007-04-08.
  2. ^ Hulubei, H.; Cauchois, Y. (1939). "Nouvelles recherches sur l'élément 93 naturel". Comptes rendus. 209: 476–479.
  3. ^ Mcmillan, Edwin; Abelson, Philip (1940). "Radioactive Element 93". Physical Review. 57 (12): 1185. Bibcode:1940PhRv...57.1185M. doi:10.1103/PhysRev.57.1185.2.