Osmium

Osmium sits in group 8 of the periodic table as a transition metal. It proudly belongs to the prestigious platinum group of chemical elements. You will typically find osmium in nature as a completely uncombined metal.

You can also discover it in natural alloys like iridosmine and osmiridium. Miners often extract these specific ores right alongside natural platinum deposits. Osmium boasts an extraordinarily high melting point compared to most other metals.

It also shows a remarkable resistance to both corrosion and harsh chemical attack. The metal has one of the lowest compressibilities of any known element. Compressibility measures how much a substance shrinks when put under extreme pressure.

This very low compressibility makes solid osmium exceptionally stiff and physically hard. Solid bulk osmium remains highly unreactive under normal room temperature atmospheric conditions. However, finely divided osmium powder behaves much differently in the open air.

The powder reacts slowly with atmospheric oxygen at normal room temperatures. This slow chemical reaction forms a new compound called osmium tetroxide (OsO₄). Osmium tetroxide is an extremely toxic chemical with a strong, pungent odor.

This compound is highly volatile, which means it evaporates into a gas very easily. Osmium displays an unusually wide range of different chemical oxidation states. An oxidation state describes how many electrons an atom has lost or gained.

These available states range from -2 all the way up to a +8 charge. The +4 and +8 states are the most common in typical osmium compounds. Engineers rarely use pure osmium in its natural elemental form today.

The pure metal is incredibly scarce and very difficult to shape or machine. Furthermore, the highly toxic nature of its oxide makes it dangerous to handle.