Australium
First revealed by the story depicted within the TeamFortress 2 web comic; "Loose Canon", Australium is an advanced type of metal element which can adapt and transform itself to different states and forms. Therefore making this element extremely valuable and sought-after.
The Australium metal element was discovered by the country of Australia, explaining the element's self referential name to the country.
The discovery of Australium has most likely been the cause and reason behind Australia's rapid speed increase of technology advancement. Australium is believed to have also played a large part in the process of the Australian country creating cloaking devices, teleportation devices, and the entire spectrum of moustache sciences.
Australium is believed to be sold and exchanged within the form of solid bars, similar to the way the gold element is often reserved and stored. Despite sharing similar appearance properties to gold, such as a similar color and the level of reflectivity, bars of Australium can be identified by the unique logo of a lone figure boxing a Kangaroo. One of Australia's most known and iconic animals. This act of boxing between the Kangaroo and the figure, is supposedly how Australia is believed to choose it's next rightful king.
Australians are known to be very secretive about the Australium element, most likely in order to keep the element in high value and demand. Therefore allowing them to continue to outpace the rest of the world in the race for further technology advancement.
The Australium element was also used in terms of payment to Dell Conagher's ancestor, in exchange for him to build each Blutarch and Redmond a life extending machine, to further their own attempts to try and outlive and inherit each other's land.
Dell Conagher's ancestor is believed to have found many more caches of the Australium element, which Dell Conagher himself can been seen discovering a record of these caches, hidden amongst the blueprints Blutarch has lent to him to repair his own life extending machine.
Trivia
It is believed that the Golden wrench is likely to be also made of the same Australium element, due to it's ability to transform any struck victim into solid gold by the killing blow.
Australium seems to carry many references to the current owner and acting head of Mann Co, Saxton Hale. For instance the nature to fight with almost anything and anyone, including Cougars and Kangaroos. The latter seen on one of the bars of Australium offered by Redmond's representative within the story, as payment to mister Dell Conagher.
The self referential naming of discovered entities is also rather common in today's modern discoveries, such as recently discovered planets, stars and elements that are also named after the person or group which first discovered them.
