Dianium was the proposed name for a new element found by the mineralogist and poet

Wolfgang Franz von Kobell Wolfgang Xavier Franz Ritter von Kobell (19 July 180311 November 1882) was a German mineralogist and writer of short stories and poems in Bavarian dialect. Biography Kobell was born in Munich, Bavaria (where he also died), son of the painter ...

in 1860. The name derived from the Roman goddess Diana. During the analysis of the mineral

tantalite The mineral group tantalite Fe,_manganese.html"_;"title="iron.html"_;"title="iron">Fe,_manganese">Mn)Tantalum">Ta2oxygen.html" ;"title="manganese">Mn)Tantalum.html" ;"title="iron">Fe,_manganese.html" ;"title="iron.html" ;"title="iron">Fe, manga ...

and

niobite Columbite, also called niobite, niobite-tantalite and columbate [], is a black mineral group that is an ore of niobium. It has a submetallic Lustre (mineralogy), luster and a high density and is a niobate of iron and manganese. This mineral group ...

he concluded that it does contain an element similar to

niobium Niobium is a chemical element with chemical symbol Nb (formerly columbium, Cb) and atomic number 41. It is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to pure titanium, and it has sim ...

and

tantalum Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as ''tantalium'', it is named after Tantalus, a villain in Greek mythology. Tantalum is a very hard, ductile, lustrous, blue-gray transition metal that is ...

. The symbol was Di. Following the rediscovery of niobium in 1846 by the German chemist

Heinrich Rose Heinrich Rose (6 August 1795 – 27 January 1864) was a German mineralogist and analytical chemist. He was the brother of the mineralogist Gustav Rose and a son of Valentin Rose. Rose's early works on phosphorescence were noted in the Quarter ...

Friedrich Wöhler Friedrich Wöhler () FRS(For) HonFRSE (31 July 180023 September 1882) was a German chemist known for his work in inorganic chemistry, being the first to isolate the chemical elements beryllium and yttrium in pure metallic form. He was the firs ...

, Heinrich Rose, R. Hermann and Kobell analysed the minerals

and

columbite Columbite, also called niobite, niobite-tantalite and columbate [], is a black mineral group that is an ore of niobium. It has a submetallic Lustre (mineralogy), luster and a high density and is a niobate of iron and manganese. This mineral group w ...

to better understand the chemistry of niobium and tantalum. The similar reactivity of niobium and tantalum hindered preparation of pure samples and therefore several new elements were proposed, which were later found to be mixtures of niobium and tantalum. Rose discovered

pelopium Pelopium was the proposed name for a new element found by the chemist Heinrich Rose in 1845. The name derived from the Greek king and later god Pelops, son of Tantalus. During the analysis of the mineral tantalite he concluded that it does contain ...

in 1846, while Hermann announced the discovery of

ilmenium Ilmenium was the proposed name for a new element found by the chemist R. Hermann in 1847. During the analysis of the mineral samarskite, he concluded that it does contain an element similar to niobium and tantalum. The similar reactivity of niobium ...

in 1847. In 1860 Kobell published the results on the tantalite from a quarry near

Kimito Kimito (; fi, Kemiö ) is a former municipality of Finland. On January 1, 2009, it was consolidated with Dragsfjärd and Västanfjärd to form the new municipality of Kimitoön. Prior to the consolidation, it was one of the four municipalities l ...

a village in

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

and columbite from

Bodenmais Bodenmais is a municipality in the district of Regen in Bavaria in Germany. It lies at one end of the Zeller Valley in the Bavarian Forest. The tourist attractions at the Silberberg mountain include cross-country skiing tracks as well as an alpi ...

a village in Germany. He concluded that the element he found was different from tantalum, niobium, pelopium and ilmenium. 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 Christian Wilhelm Blomstrand (20 October 1826 – 5 November 1897) was a Swedish mineralogist and chemist. He was a professor at the University of Lund from 1862-1895, where he isolated the element niobium in 1864. He developed an early version of ...

, and

Henri Etienne Sainte-Claire Deville Henri is an Estonian, Finnish, French, German and Luxembourgish form of the masculine given name Henry. People with this given name ; French noblemen :'' See the 'List of rulers named Henry' for Kings of France named Henri.'' * Henri I de Montm ...

, as well as by

Louis J. Troost Louis Joseph Troost (17 October 1825, Paris – 30 September 1911) was a French chemist. Biography In 1848 he began his studies at the École Normale Supérieure in Paris, where from 1851 he worked as an assistant chemist. In 1856 he receiv ...

, who determined the formulas of some of the compounds in 1865 and finally by the Swiss chemist

Jean Charles Galissard de Marignac Jean Charles Galissard de Marignac (24 April 1817 – 15 April 1894) was a Swiss chemist whose work with atomic weights suggested the possibility of isotopes and the packing fraction of nuclei. His study of the rare earth elements led to h ...

Both tantalum and niobium react with

chlorine Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...

and traces of oxygen, including atmospheric concentrations, with niobium forming two compounds: the white volatile

niobium pentachloride Niobium(V) chloride, also known as niobium pentachloride, is a yellow crystalline solid. It hydrolyzes in air, and samples are often contaminated with small amounts of NbOCl3. It is often used as a precursor to other compounds of niobium. NbCl ...

(NbCl₅) and the non-volatile

niobium oxychloride Niobium oxychloride is the inorganic compound with the formula NbOCl3. It is a white, crystalline, diamagnetic solid. It is often found as an impurity in samples of niobium pentachloride, a common reagent in niobium chemistry. Structure In th ...

(NbOCl₃). The claimed new elements ''pelopium'', ''

'' and ''dianium'' were in fact identical to niobium or mixtures of niobium and tantalum.

References

{{reflist Misidentified chemical elements