Holmium
For eye-safe lasers.
| Atomic Number: |
67 |
| Atomic Symbol: |
Ho |
| Atomic Weight: |
164.9304 |
| Electron Configuration: |
[Xe]6s24f11 |
History
(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.
Properties
Pure holmium has a metallic to bright silver luster. It is relatively soft and
malleable, and is stable in dry air at room temperature, but rapidly oxidizes in moist air
and at elevated temperatures. The metal has unusual magnetic properties. Few uses have yet
been found for the element. The element, as with other rare earths, seems to have a low
acute toxic rating.
Cost
The price of 99+% holmium metal is about $10/g.
Sources: CRC Handbook of Chemistry
and Physics and the American Chemical Society.
Last Updated: 12/19/97, CST Information Services Team
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