Gadolinite holmium

L. Holmia, for Stockholm). The special absorption bands of holmium were noticed in 1878 by the Swiss chemists Delafontaine and Soret, who announced the existence of an "Element X." Cleve, of Sweden, later independently discovered the element while working on erbia earth. The element is named after cleve s native city. Holmia, the yellow oxide, was prepared by Homberg in 1911. Holmium occurs in gadolinite, monazite, and in other rare-earth minerals. It is commercially obtained from monazite, occurring in that mineral to the extent of about 0.05%. It has been isolated by the reduction of its anhydrous chloride or fluoride with calcium metal. 

Holmium is the 12th most abundant of the rare-earths found in the Earths crust. Although it is the 50th most abundant element on Earth, it is one of the least abundant lanthanide metals. It is found in gadolinite and the monazite sands of South Africa and Austraha and in the beach sands of Florida and the Carolinas in the United States. Monazite sand contains about a 50% mixture of the rare-earths, but only 0.05% by weight is holmium. Today, small quantities of holmium are produced by the ion-exchange process. 

Holmium was discovered by Swedish chemist Per Teodor Cleve (1840-1905) in 1879. He named the element after his birthplace, Stockholm, Sweden. Holmium occurs with other rare earth elements in minerals such as monazite and gadolinite. ft can now be separated from other rare earth elements somewhat easily. But no major uses have been found for it or its compounds. 

The abundance of holmium in Earth s crust is estimated to be about 0.7 to 1.2 parts per million. It is less common than most other rare earth elements, but more common than iodine, silver, mercury, and gold. The most common ores of holmium are monazite and gadolinite. 

Most of the rare earth elements were discovered in the mineral gadolinite, (Ce,La, Nd,Y)2FeBe2Si20io (Mindat.Org) from Ytterby. The town has given name to yttrium, ytterbium, terbium, and erbium. Other elements discovered here are gadolinium, holmium, thulium, scandium, lutetium, and tantalum (Source Mindat.org). 

Let us now leap forward in time to be able to close the matter of the division of erbium. Lecoq de Boisbaudran developed a fantastically intricate and wearisome method for the separation of gadolinite rare earth elements, consisting of 32 precipitations with ammonia and 26 subsequent precipitations with oxalate, separation of the fractions and their spectroscopic and fluorescence studies. In 1886, he came to the conclusion that holmium is not homogeneous either, it contains another element which he named dysprosium. This element was apparently accepted by the chemists of the world without the usual unbelief and debate (Lecoq de Boisbaudran 1886). 

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