Holmium (Ho, atomic number 67) is a lanthanide and is classed as a ‘heavy rare earth’ element. It was discovered in 1879 by a Swedish chemist, Per Theodor Cleve, who named it after the Latin name for his native city, Stockholm.
Holmium is a soft, ductile, silvery white metal that, like all rare earths, does not exist in its pure state in nature. It is notable for having the highest magnetic strength of all the elements and its remarkable absorption abilities.
Holmium occurs in the Earth’s crust at an average concentration of 1.4 p.p.m., which makes it the 56th most abundant element and relatively scarce for a rare earth element. Its major mining area is China, with supplies also coming from the US, Brazil, India, Sri Lanka, and Australia. On average, about 10 tons are produced a year, which are primarily obtained through an ion exchange process from monazite sands.
In recent years, a number of new technologies have incorporated Holmium. Due to its magnetic strength, Holmium has been used to create the strongest ever artificial magnetic field. It has been used in the nuclear energy industry, where is has been incorporated in nuclear control rods due to its capability to absorb neutrons expelled by nuclear fission.
Holmium has proven to be useful in the medical industry where it is used in new laser technology and medical devices. Holmium lasers have been developed recently that are capable of being used on the human eyes to correct Hyperopia. Furthermore, Holmium lasers can be used in non-invasive medical procedures treating cancers and kidney stones. Holmium is also used to colour glass and ceramics. The remarkable magnetic properties of this element are likely to be further exploited in the future.
Relative atomic mass