Magnesium is the third most commonly used structural metal, following steel and aluminium.  It is the eighth most abundant element in the earth’s crust but is rarely found in its pure form due to the fact that it bonds with other elements easily. 

 

It was first produced in 1808 in small quantities by Sir Humphrey Davy and industrial production first began in 1886 in Germany.  Magnesium was first found in an area of Thessaly/Greece called Magnesia. The ore got its name from this location and can still be found in great quantities there.

 

Magnesium is used in both its pure form and as an alloy.  Depending on the composition of the metal, there can be notable differences in many physical properties, but elemental magnesium is a silvery-white alkaline metal, symbolised by Mg on periodic table.  It has an atomic weight of 24.305 and a hexagonal close packed crystal structure in pure form and with a density of 1.7g/cm³ is the least dense of the structural metals.

 

Most magnesium produced globally comes from natural minerals such as dolomite and magnesite in the form of magnesium carbonate.  It can also be found in seawater which contains 0.13% of the element in the form of magnesium chloride, and in salt lakes brines or underground mineral salt deposits. 

 

There are many advantages to using magnesium and its alloys. With the lowest density of all commercial casting alloys, magnesium is 33% lighter than aluminium and 75 percent lighter than steel. Despite the lower density, magnesium alloys have a comparable strength to weight ratio to aluminium.