Sequanium

Sequanium was the proposed name for a new element that Romanian physicist Horia Hulubei reported he had discovered 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. Element 93 was synthesised in 1940 and named neptunium.^[3] It does in fact occur in nature in trace amounts, but it is not commonly believed that Hulubei actually discovered it.