Holmium

Chemical element symbol is (Ho) and atomic number 67.

Holmium is Rare Earth Metal classified in the group of Heavy Rare Earth Elements (REE).

Marc Delafontaine and Jacques Louis Soret identified the Holmium in 1878 by spectral analysis of the earth yttrium obtained from gadolinite. Later, Per Theodor Cleve who named individual honour of his country, Sweden, has established the presence of its oxide, independently. It was only in 1911 that the oxide was obtained in reasonably pure state. It is mined as most of the Rare Earths, monazite that contains about 0.05%.

The Holmium is a silvery white metal relatively soft and pliable but strong enough to corrosion and stable in dry air at standard temperature and pressure. In moist air and at higher temperatures itis rapidly oxidized, forming a yellowish oxide. In its pure form, it has light silvery sheen. When combined with yttrium, it forms highly magnetic compounds.

Holmium oxide changes fairly dramatic colour depending on lighting condition. In daylight, it is a brownish yellow colour. Under trichromatic light, it is an orange red light.

Like all other Rare Earths, holmium is not naturally found as a free element in the Earthly crust. It is constituted only in combination with other elements, gadolinite, monazite and other Rare Earth minerals.