By Paul Rincon
Science reporter, BBC News
Two of the best known crystal skulls - artefacts once thought to be
the work of ancient American civilisations - are modern fakes, a
scientific study shows.
Crystal skulls are the focus of the story in the latest Indiana
Jones film.
But experts say examples held at the British Museum in London and
the Smithsonian Institution in Washington DC are anything but
genuine.
Their results show the skulls were made using tools not available to
the ancient Aztecs or Mayans.
Researchers say the work, which is published in the Journal of
Archaeological Science, should end decades of speculation over the
origins of these controversial objects.
A team including Margaret Sax, from the British Museum in London,
and Professor Ian Freestone, from Cardiff University, used
sophisticated techniques to work out how the two skulls had been
made.
“There seems to be the assumption that if it is roughly worked, it
is more likely to have been made by a traditional society. That’s
untrue of course” Prof Ian Freestone, Cardiff University
“There are about a dozen or more of these crystal skulls. Except for
the British Museum skull and one in Paris, they seem to have entered
public awareness since the 60s, with the interest in quartz and the
New Age movement,” Professor Freestone told BBC News.
“It does appear that people have been making them since then. Some
of them are quite good, but some of them look like they were
produced with a Black & Decker in someone’s garage.”
He added: “There seems to be the assumption that if it is roughly
worked, it is more likely to have been made by a traditional
society. That’s untrue of course, because people were quite
sophisticated. They might not have had modern tools, but they did a
good job.”
The researchers used an electron microscope to show that the skulls
were probably shaped using a spinning disc-shaped tool made from
copper or another suitable metal.
The craftsman added an abrasive to the wheel, allowing the crystal
to be worked more easily.
Modern technology
This “rotary wheel” technology was almost certainly not used by
pre-Columbian peoples. Instead, analysis of genuine Aztec and Mixtec
artefacts show they were crafted using tools made from stone and
wood.
The British Museum skull was worked with a harsh abrasive such as
corundum or diamond. But X-ray diffraction analysis showed a
different material, called carborundum, was used on the artefact in
the Smithsonian.
Carborundum is a synthetic abrasive which only came into use in the
20th Century: “The suggestion is that it was made in the 1950s or
later,” said Professor Freestone.
Who made the skulls is still a mystery. But, in the case of the
British Museum object, some point the finger of suspicion at a 19th
Century French antiquities dealer called Eugene Boban.
“We assume that he bought it from, or had it made from [craftsmen]
somewhere in Europe,” said Professor Freestone, a former deputy
keeper of science and conservation at the British Museum.
Anonymous donation
Contemporary documents suggest Mr Boban was involved in selling at
least two of the known crystal skulls - the one held in London and
another in Paris.
The London skull was probably manufactured no more than a decade
before being offered up for sale.
Despite the findings, a spokeswoman for the British Museum said the
artefact would remain on permanent display to the public.
The skull held by the Smithsonian was donated to the museum
anonymously in 1992, along with a note saying it had been bought in
Mexico in 1960.
Nothing is known of its history before that date, but like the
British object, it was probably manufactured shortly before being
purchased.
The researchers were not able to determine where the quartz used in
the skulls was quarried. But locations with suitably large deposits
include Brazil, Madagascar and, possibly, the Alps.
Professor Freestone said the work did not prove all crystal skulls
were fakes, but it did cast doubt on the authenticity of other
examples: “None of them have a good archaeological provenance and
most appeared suspiciously in the last decades of the 20th Century.
So we have to be sceptical,” he explained.
The findings are likely to be a disappointment to enthusiasts and
collectors; the skulls have become a part of popular culture,
appearing in numerous films and novels.