Aluminium is a silver-coloured, low density (2.7 g/cc) metal that finds use in a huge variety of commercial applications. Unalloyed aluminium is ductile, exhibits moderate strength, and is very resistant to corrosion under most circumstances. Aluminium can be strengthened by the addition of appropriate alloying elements (Cu, Mg, Mn, Si, etc.) and subsequent heat/work treatments. Aluminium is commonly used in both wrought and cast forms.