Osmium is a chemical element located in the group of platinum metals of Groups 8-10 (VIIIb), Periods 5 and 6, of the periodic table and is considered the densest natural element on earth. It is a gray-white metal, very hard and strong, difficult to work with, even at high temperatures. Platinum metals have the highest melting point, so melting it is very difficult. The alloys obtained from osmium are very resistant and should be treated before working with it because in its pure state cannot be modified, for this reason must be melted or powdered.

  • Symbol: Os
  • Atomic number: 76
  • Group: 8

What is osmium?

Osmium is a chemical element in the form of a metal located in groups 8 and 10 of the periodic table of elements. It is considered to be the densest and hardest element on earth, so much that in order to work with it must first be melted or powdered.

Osmium characteristics


It was discovered by the British chemist Smithson Tennant in 1803. At that time, osmium and iridium were identified in the black residue remaining after dissolving platinum ore with water, a mixture of 25% nitric acid (HNO3) and 75% hydrochloric acid (HCl). Osmium comes from the Greek term osme, which means smell and odor.

Who discovered osmium?

Smithson Tennant discovered it in 1803.


Alloys which can be obtained by joining osmium with other elements such as rhodium, ruthenium, iridium or platinum are used in the manufacture of fountain pens, compass tips, phonographic needles, electrical contacts and instrument pivots. They are used in the creation of these materials because of the extreme hardness of this element and its great resistance to corrosion. Osmium tetroxide, OsO4, is highly toxic to people, concentrations in the air as low as 10-7 g/m3 can cause lung congestion, skin damage, and serious eye damage, for this reason should be handled only by properly qualified chemists. It is prepared by quite complex chemical processes from platinum minerals in which it is found in very small proportions and as a by-product in the osmium-rich ores of nickel and copper minerals.

What is it for?

Where it is found?

This element can be obtained in sands containing platinum, iridium and a small amount of other metals. After an extensive process of enrichment of the sands it is passed to the treatment with treated water, and in this way the platinum is obtained. It must then be separated from ruthenium by reduction with alcohols and precipitated in the form of OsO4. Purification is by distillation.

Written by Gabriela Briceño V.

How to cite this article?

Briceño V., Gabriela. (2019). Osmium. Recovered on 23 February, 2024, de Euston96:

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