Dianium was the proposed name for a new element found by the mineralogist and poet Wolfgang Franz von Kobell in 1860.
During the analysis of the mineral tantalite and niobite, he concluded that it does contain an element similar to niobium and tantalum.
Following the rediscovery of niobium in 1846 by the German chemist Heinrich Rose, Friedrich Wöhler, Heinrich Rose, R. Hermann and Kobell analysed the minerals tantalite and columbite to better understand the chemistry of niobium and tantalum.
He concluded that the element he found was different from tantalum, niobium, pelopium and ilmenium.
[1][3] The differences between tantalum and niobium and the fact that no other similar element was present were unequivocally demonstrated in 1864 by Christian Wilhelm Blomstrand,[4] and Henri Etienne Sainte-Claire Deville, as well as by Louis J. Troost, who determined the formulas of some of the compounds in 1865[4][5] and finally by the Swiss chemist Jean Charles Galissard de Marignac.