The age of aluminium

Aluminium has been known in its modern incarnation since the 18th century. Since the light metal only occurs in compound form in nature and since it can only be obtained with a very large technical effort, it is assumed that articles made of aluminium cannot be much older than 250 years. Apparently far from the truth – as a look at three archaeological finds shows:

In 1937-1983, a Chinese archaeologist undertaking an expedition to the mountains of Baian Kara Ula discovered skeletal remains and what were originally called "odd stone discs" with engraved images of small human-like beings, animals and plants as well as hieroglyphs which are around 12,000 years old. Scientists from Moscow found that the discs comprised a combination of aluminium, silicon and a high proportion of cobalt. It should actually have been impossible for humans to produce such a combination of these materials at that time.

In 1956, archaeologists in the Chinese province of Kiangsu were excavating graves of the Tsin dynasty under Emperor Chou Chou and found artefacts which were around 1,600 years old. The artefacts included an elaborate belt buckle whose ornaments were made of 85% aluminium.

To the east of the Romanian town of Aiud, three objects were found at a depth of around ten metres in 1974. One of them turned out to be a real puzzle: a work of an alloy consisting of 89% aluminium. This fact is so unusual because the two other objects found were fragments of bone from a mastodon (a kind of prehistoric elephant), an animal which died out millions of years ago. The aluminium work, on the other hand, was clearly man-made, i.e. was identified as artificial. Another inexplicable fact is that the aluminium object was covered by an oxide coating which was said to be more than one millimetre thick. A surface oxide coating of this thickness was previously unknown and would require extremely long exposure to oxygen. This can only mean that this object must be incredibly old.

As often happens in history, there is no final and permanent answer. The important thing is to remain willing to rethink what was considered valid on the basis of new information and to revise the answer where necessary.

Overview