What is "holmium"

Holmium \Hol"mi*um\, n. [NL., from Stockholm.] (Chem.) A rare element of atomic number 67 said to be contained in gadolinite. Chemical symbol Ho. Atomic weight 164.93. Valence +3. It was detected by spectral absorption bands in 1878 by the Delafontaine and Soret, who called it "Element X". Later the Swedish chemist Cleve independently discovered it in erbia, and named it after his native city Stockholm. The first preparation of pure Holmia, the yellow oxide, was not made until 1911.
--HCP61 -- Hol"mic, a.

rare earth element, named by French chemist Lecoq de Boisbaudran (1838-1912) in 1886, from holmia "holmium oxide," a Modern Latin word coined by the earth's discoverer, Swedish chemist Per Teodor Cleve (1840-1905), in 1879 from Holmia, Latin name of Stockholm.

n. A metallic chemical element (''symbol'' Ho) with an atomic number of 67.

n. a trivalent metallic element of the rare earth group; occurs together with yttrium; forms highly magnetic compounds [syn: Ho, atomic number 67]

Holmium is a chemical element with symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare earth element. Holmium was discovered by Swedish chemist Per Theodor Cleve. Its oxide was first isolated from rare earth ores in 1878 and the element was named after the city of Stockholm.

Elemental holmium is a relatively soft and malleable silvery-white metal. It is too reactive to be found uncombined in nature, but when isolated, is relatively stable in dry air at room temperature. However, it reacts with water and rusts readily, and will also burn in air when heated.

Holmium is found in the minerals monazite and gadolinite, and is usually commercially extracted from monazite using ion exchange techniques. Its compounds in nature, and in nearly all of its laboratory chemistry, are trivalently oxidized, containing Ho(III) ions. Trivalent holmium ions have fluorescent properties similar to many other rare earth ions (while yielding their own set of unique emission light lines), and holmium ions are thus used in the same way as some other rare earths in certain laser and glass colorant applications.

Holmium has the highest magnetic permeability of any element and therefore is used for the polepieces of the strongest static magnets. Because holmium strongly absorbs neutrons, it is also used as a burnable poison in nuclear reactors.