Although magnesium is found in over 60 minerals, only Dolomite, Magnesite, Brucite, Carnalite, Talc and Olivine are of commercial importance.
The chief use for the metal is as an alloying agent to make aluminium-magnesium alloys. This alloy is prized for its properties of lightness combined with strength.
Magnesium compounds are used medicinally as common laxatives, antacids (e.g. milk of magnesia), and to stabilize abnormal nerve excitation or blood vessel spasm such as eclampsia.
Magnesium has both the lowest melting and the lowest boiling points of any of the alkali earth metals.
It is highly flammable when powdered or shaved into Tin strips but difficult to ignite in mass or bulk.
Once ignited, it is difficult to extinguish – Incendiary Weapon.
Ignition source for Thermite, a mixture of aluminium and iron oxide that is difficult to ignite.
Magnesium is the third most commonly used structural metal, following iron and aluminium. It has been called the lightest useful metal.
The main application of magnesium ore, in order:
Component of Aluminium alloys.
In die-casting (alloyed with zinc).
To remove sulfur in the production of iron and steel.
The production of Titanium in the Kroll Process.
Because of low weight and good mechanical and electrical properties, magnesium is widely used for manufacturing of mobile phones and other.
Other used include flash photography, flares, pyrotechnics and fireworks sparklers.
Used as a sacrificial (galvanic anode) to protect underground tanks, pipelines and other.
With Zinc, used in dry-cell battery walls, and roofing.