- Holmium was discovered by Delafontaine
and Soret in 1878 AD. It is a soft silvery metallic element, which
is found in the lanthanide series of inner transition metals in Group III a of the periodic
table.
- Holmium occurs with the rare earths in
their ores. It is separated from other rare earths by ion exchange
chromatography. It is prepared by reducing the anhydrous chloride
with calcium .which is stable in air. It has unusual magnetic
properties. It is used in the filters used for the calibration of
the wavelength settings in UV spectrophotometers.
- It 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.
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