Pelopium
Encyclopedia
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
. During the analysis of the mineral tantalite
he concluded that it does contain an element similar to niobium
and tantalum
. The similar reactivity of niobium and tantalum complicated preparation of pure samples and therefore several new elements were proposed, which were later found to be mixtures of niobium and tantalum.
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
, and Henri Etienne Sainte-Claire Deville
, as well as Louis J. Troost, who determined the formulas of some of the compounds in 1865 and finally by the Swiss chemist Jean Charles Galissard de Marignac
This confusion arose from the minimal observed differences between tantalum and niobium. Both tantalum and niobium react with chlorine
and traces of oxygen, including atmospheric concentrations, with niobium forming two compounds: the white volatile niobium pentachloride (NbCl5) and the non-volatile niobium oxychloride
(NbOCl3). The claimed new elements pelopium, ilmenium
and dianium
were in fact identical to niobium or mixtures of niobium and tantalum.
Heinrich Rose
Heinrich Rose was a German mineralogist and analytical chemist. He was the brother of the mineralogist Gustav Rose and a son of Valentin Rose....
in 1845. The name derived from the Greek king and later god Pelops
Pelops
In Greek mythology, Pelops , was king of Pisa in the Peloponnesus. He was the founder of the House of Atreus through his son of that name....
. During the analysis of the mineral tantalite
Tantalite
Tantalite, [2O6], is a mineral group that is close to columbite. The two are often grouped together as a semi-singular mineral called coltan or "columbite-tantalite" in many mineral guides. However, tantalite has a much greater specific gravity than columbite...
he concluded that it does contain an element similar to niobium
Niobium
Niobium or columbium , is a chemical element with the symbol Nb and atomic number 41. It's a soft, grey, ductile transition metal, which is often found in the pyrochlore mineral, the main commercial source for niobium, and columbite...
and tantalum
Tantalum
Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as tantalium, the name comes from Tantalus, a character in Greek mythology. Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion resistant. It is part of the refractory...
. The similar reactivity of niobium and tantalum complicated preparation of pure samples and therefore several new elements were proposed, which were later found to be mixtures of niobium and tantalum.
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
Christian Wilhelm Blomstrand was a Swedish mineralogist and chemist.Blomstrand was born in Växjö, Sweden and studied chemistry at the University of Lund, where he received his Ph.D in 1850 and his habilitation in 1854. After a expedition to Spitsbergen and a being a lecturer at the Elementary...
, and Henri Etienne Sainte-Claire Deville
Henri Etienne Sainte-Claire Deville
Henri Étienne Sainte-Claire Deville was a French chemist.He was born in the island of St Thomas, West Indies, where his father was French consul. Together with his elder brother Charles he was educated in Paris at the College Rollin...
, as well as Louis J. Troost, 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
Jean Charles Galissard de Marignac was a Swiss chemist whose work with atomic weights suggested the possibility of isotopes and the packing fraction of nuclei and whose study of the rare earth elements led to his discovery of ytterbium in 1878 and codiscovery of gadolinium in 1880.- Life and work...
This confusion arose from the minimal observed differences between tantalum and niobium. Both tantalum and niobium react with chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
and traces of oxygen, including atmospheric concentrations, with niobium forming two compounds: the white volatile niobium pentachloride (NbCl5) and the non-volatile niobium oxychloride
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 and synthesis :...
(NbOCl3). The claimed new elements pelopium, ilmenium
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...
and dianium
Dianium
Dianium was the proposed name for a new element found by the mineralogist and poet Wolfgang Franz von Kobell in 1860. The name derived from the Greek goddess Diana...
were in fact identical to niobium or mixtures of niobium and tantalum.