Didymium

Gr. neos, new, and didymos, twin) In 1841, Mosander, extracted from cerite a new rose-colored oxide, which he believed contained a new element. He named the element didymium, as it was an inseparable twin brother of lanthanum. In 1885 von Welsbach separated didymium into two new elemental components, neodymia and praseodymia, by repeated fractionation of ammonium didymium nitrate. While the free metal is in misch metal, long known and used as a pyrophoric alloy for light flints, the element was not isolated in relatively pure form until 1925. Neodymium is present in misch metal to the extent of about 18%. It is present in the minerals monazite and bastnasite, which are principal sources of rare-earth metals. 

It is easy to reduce anhydrous rare-earth hatides to the metal by reaction of mote electropositive metals such as calcium, lithium, sodium, potassium, and aluminum. Electrolytic reduction is an alternative in the production of the light lanthanide metals, including didymium, a Nd—Pt mixture. The rare-earth metals have a great affinity for oxygen, sulfur, nitrogen, carbon, silicon, boron, phosphoms, and hydrogen at elevated temperature and remove these elements from most other metals. 

Lanthanum - the atomic number is 57 and the chemical symbol is La. The name derives from the Greek lanthanein for to be hidden or to escape notice because it hid in cerium ore and was difficult to separate from that rare earth mineral. It was discovered by the Swedish surgeon and chemist Carl-Gustav Mosander in 1839. In 1842, Mosander separated his lanthanium sample into two oxides for one of these he retained the name lanthanum and for the other he gave the name didymium (or twin). 

Neodymium - the atomic number is 60 and the chemical symbol is Nd. The name was originally neodidymium and was later shortened to neodymium, which is derived from the Greek neos for new and didymos for twin . It was discovered by the Swedish surgeon and chemist Carl Gustav Mosander in 1841, who called it didymium (or twin) because of its similarity to lanthanium which he had previously discovered two years earlier. In 1885, the Austrian chemist Carl Auer von Welsbach separated didymium into two elements. One of which he called neodymium (or new twin). 

A commercial mixture of several of the rare-earth elements is called didymium (Di). It is neither an element nor a compound, but is used to name the mixture of oxides and salts of most of the rare-earth elements that are extracted from the ore monazite. Another unique substance, called misch metal, is an alloy of iron and several rare-earth elements (La, Ce, and Pr). This mixture is pyrophoric, which means it sparks when scratched. This is why it is used for cigarette-lighter flints. 

At first praseodymium was called didymium, which is Greek for twin, because it was always found with another rare-earth element. Using spectroscopic analysis, the two different color bands, one green and one yellow, indicated that there were two elements in didymium, but no one could identify the new elements. 

In 1885 Carl Auer Baron von Welsbach (1858-1929) separated the oxides of two similar elements from didymium. He named one praseodymium from the Greek word prasios, which means green or the green twin, and he named the other element neodymium, which is derived from new and dymium and means new twin. ... 

In 1885 Carl Auer Baron van Welsbach separated a common rare-earth called didymium into two distinct rare-earths. One he called green didymia (praseodymium) and the other he named new didymia (neodymium). The green color of green didymia (praseodymium) is caused by contamination of iron. 

The element was discovered hy von Welshach in 1885 after he succeeded in fractionating ammonium didymium nitrate, thus splitting didymia into two new rare earths. Earlier, in 1841, Mosander extracted a rose-colored oxide from cerite, which he named didymium and which actually was a mixture of two rare earth elements. These two new elements were named hy von Welshach as praseodymia (green twin) and neodymia (new twin). 

Ishibashi, M. Iwasaki, T. Imai, S. Sakamoto, S. Yamaguchi, K. Ito, A. (2001) Laboratory culture of the Myxomycetes formation of fruitmg bodies of Didymium bahiense and its plasmodial production of makaluvamine A. J. Nat. Prod., 64, 108-10. 

Swedish physicist, astronomer, and spec-troscopist. He mapped the spectra of yttrium, erbium, didymium, lanthanum, scandium, thulium, and ytterbium, and in 1866 wrote a histoncal review of spectrum analysis. He also studied the magnetic properties of iron and iron ores. 

In 1841 Mosander had treated lanthana with dilute nitric acid, and had extracted from it a new rose-colored oxide, which he believed contained a new element. He named the new metal didymium because, as he said, it seemed to be an inseparable twin brother of lanthanum (27, 29, 46). 

Marignac, Lecoq de Boisbaudran, Cleve, and Bohuslav Brauner all believed didymium to be a mixture of elements, but none of them were able to make the difficult separation (49). In 1882 Professor Brauner of the University of Prague examined some of his didymia fractions with the spectroscope and found a group of absorption bands in the blue region (A=449-443) and another in the yellow (A.=590-568) (53, 66)." These two groups of bands are now known to belong to two earths, praseodymia and neodymia, respectively, which Baron Auer von Welsbach obtained in 1885 by splitting didymia (3, 30, 32, 58). 

On June 18, 1885, he announced to the Vienna Academy of Sciences that by repeated fractionation of ammonium didymium nitrate he had succeeded in splitting didymia into two earths, for which he proposed the names praseodymia and neodymia, green didymia and new didymia. Many chemists were skeptical, and he afterward said, Only Bunsen, to... 

Mosander, C. G., On the new metals lanthanium and didymium, which are associated with cerium and on erbium and terbium, new metals associated with yttria, Phil. Mag., [3], 23, 241-54 (Oct., 1843). 

Sept. 10, 1797 Birth of Carl Gustav Mosander, the discoverer of lanthanum and didymium, at Kalmar, Sweden. 

But he did not formally announce the new element for two years, because he suspected that it was not wholly pure. In 1841 he revealed that it was mixed with another earth , containing an element that he called didymium (from the Greek didumos, twin ). 

Yet that was not the end of it. Other chemists suspected that didymium too was not a pure element, but a mixture. Separating its components chemically was very difficult, as they seemed to behave almost identically. But their presence was revealed by inspecting the bar code of elemental emission lines in the glow produced when the material was heated. 

In 1879 Paul-Emile Lecoq, gallium s discoverer, announced that there was another element contaminating didymium, which he called samarium. A year later Charles Galissard de Marignac in... 

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