Welcome to the #9 email in our series on Sculptors' Materials. This week, we are looking at the use of aluminium in sculpture.

Aluminium is a relatively young metal compared to its older siblings iron, gold and bronze which have been used for millennia. Due to it’s strong affinity for oxygen, aluminium is rarely found in its elemental (native) state but rather as oxides, sulphates or silicates which are widespread.

The first written record referring to Alum, an aluminium sulphate, dates back to the 5th century BC when the Greek Historian Herodotus noted it a valuable Egyptian commodity most often used for fixing dyes in textile industries.

However it was not until 1824 that the Danish physicist and chemist Hans Christian Ørsted managed to extract the metal aluminium. As the process could only produce the metal in very small quantities aluminium remained rare and more expensive than gold for many years. As such jewellers and sculptors used aluminium as a precious metal and Napoleon the Third is reported to have had a set of aluminium cutlery made for dining with his most prestigious guests.

In the 1880’s discoveries made by Paul Héroult and Charles Martin Hall and later Carl Joseph Bayer meant that aluminium could be extracted on a more industrial scale and made more accessible. As a result the price of aluminium dropped and the metail became widely used in many industries and everyday items. Aluminium's ability to form hard yet light alloys with other metals made it particularly useful for aviation and demand for aluminium soared during World War I & II.

Nowadays most aluminium is produced from the ore bauxite which is mined mainly in Australia, China, Guinea and India and extracted using the Bayer and Hall-Heroult processes. Aluminium is soft, non magnetic and ductile and has a much lower density than other metals, approximately one third of that of steel, giving it one of its most important qualities for sculpture: lightness.