Osmium: The densest metal on Earth

Reference price: 14109.58 USD/kg

Osmium is a high-density rare metal and also the highest density metal in the world. This metal is extremely difficult to mine because the melting point of osmium is very high, reaching over 3000 degrees Celsius.

The density of osmium is 22.59 grams per cubic centimeter (the second highest density is iridium, 22.56 grams per cubic centimeter). The covalent radius of osmium is particularly small, which means that osmium atoms are arranged very tightly and have a considerable density.

Metal osmium is extremely brittle, and when rammed in an iron mortar, it easily turns into powder, which is blue black in color. Metal osmium is very stable in the air, with a melting point of 2700 degrees Celsius. It is insoluble in ordinary acids and will not corrode even in aqua regia. When osmium reaches 130 degrees Celsius, it will boil. The vapor of osmium is highly toxic and can strongly stimulate the mucous membranes of the human eye, leading to blindness in severe cases.

In 1803, French chemists such as Cole de Gauti studied the residue of platinum ore dissolved in aqua regia. They announced the presence of two new metals in the residue, which are different from platinum and are insoluble in aqua regia. In 1804, Tenar discovered and named them. One of them was once named ptenium and later changed to osmium, with the element symbol set to Os. PTENIUM comes from the Greek word 'volatile', which originally means' foul odor '. This is because the melting point of osmium tetraoxide OsO ₄ is only 41 ℃, which is volatile and has a foul odor.

Important features: blue silver color, high melting point, hard and fragile

Main producing countries: Russia, North America, South America

Important uses: Osmium has many different uses, but is most commonly used in hardened alloys, electrical contacts, and filaments.