Aluminium history

In his work Historica naturalis, the Roman historian Plinius the Elder (23-79 A.D.) described natural alum stone (a compound of aluminium and sulphur) as “alumen”. The Egyptians were probably using salts obtained from this mineral as a binder in artists’ colour paint and textile dyes around 1000 B.C.; the Greeks as well as the Chinese later used the salts.

There is an interesting legend associated with alum stone: Plinius described an event that was claimed to have taken place at the time of Emperor Tiberius. He reported how an unknown craftsman made an unusual gift to the emperor: it was a beautiful drinking goblet, which looked like silver but was a lot lighter. Plinius claimed the goblet was made from some sort of unbreakable glass. The craftsman reportedly said that he didn’t want to reveal anything more about it other than that it had been obtained from clay. Was the goblet possibly made from aluminium? If so, the mysterious craftsman was centuries ahead of his time, and he must also have known another, much simpler method of extracting aluminium than the one used today - a method that future generations never found out about. According to the legend, Tiberius ordered that the craftsman be beheaded: he was worried that the new metal would make silver and gold worthless!

There are, of course, one or two question marks surrounding this report by Plinius and one should not take him too literally. Today, we know for certain that in the ensuing centuries the use of alum was limited to its application as a tanning agent and as styptic medication.

It was only in the middle of the 18th century that the German chemist Andreas Sigismund Marggraf (1709-1782) discovered the basis of alum: alumina, a compound of a hitherto unknown metal with oxygen. Science was thus made aware of this metal for the first time; however, it was not recognised as being a metal in its own right because it only occurs in nature as a compound with oxygen and silica.