Aluminium is a light metal and chemical element, with the symbol Al and atomic number 13. For the same volume, it weighs roughly a third as much as steel. A watch case made from it is very light on the wrist. Anodising adds a protective oxide layer to the surface.
How light is aluminium?
A block of aluminium weighs roughly a third as much as a block of steel of the same size. A case made from it is therefore much lighter than a steel one. The metal can also be treated. Anodising gives the surface an added layer of protective oxide. Bertucci uses this approach in a 40mm field watch. Its case is a single piece of solid anodised aluminium, and the watch weighs about 51 grams.
Where it comes from
The name goes back to alum, a substance the ancient Greeks and Romans used. In Latin it was called alumen. The metal itself was found much later. In 1825 the Danish physicist Hans Christian Ørsted announced its discovery. His sample was small and not pure. In 1886, Paul Héroult in France and Charles Martin Hall in the United States each developed the same smelting process. They worked separately.
Why do Americans say aluminum?
Both spellings name the same element, Al. In 1925 the American Chemical Society went back to the spelling ‘aluminum’. That choice is why American usage differs from ‘aluminium’. A case listed as ‘anodized aluminum’ and one listed as ‘anodised aluminium’ are made of the same material. Only the spelling changes, down to the z or s in the name of the treatment.
Checked