Aluminium Aluminium is now one of the most widely used metals, but one of the hardest to refine due to it's reactivity with other elements. Even as late as the turn of the century, Aluminium was considered very valuable and in turn expensive, even more expensive than gold. In some cultures, when a function was held (for example, a party) by wealthy people, only the most honored guests would be given Aluminium cutlery, the others had to make do with gold or silver cutlery. A Description of the Aluminium ore, including a list of it's contents Pure Aluminium oxide is known as alumina (Al2O3). This is found as corundum, a crystalline. Aluminium can also occur as cryolite (Na3AlF6).