Fake crystal Aztec skulls

A fake crystal Aztec skull

A fake crystal Aztec skull

There’s a great report out about how the British Museum and the Smithsonian teamed up to prove that two crystal skulls, one at each museum, are actually fakes.

Both skulls were purportedly made by Aztecs in Mexico prior to Columbus’ arrival. The British Museum bought its skull from Tiffany and Co. in 1897 while the Smithsonian received its skull in 1960 from an anonymous donor.

Although skulls are common motifs in Aztec art, museum curators at both institutions were suspicious of the skulls for a couple of reasons.

For one, neither skull comes from well-documented official archaeological excavations.

Also something was weird with the teeth.

To quote the report:  “The rigid linearity of features representing teeth contrasts with the more precise execution of teeth on pre-Columbian artefacts.”

It sounds like whoever faked the crystal skulls was a little too fond of idealized, modern dentistry.

To prove the two skulls were fakes, the researchers assembled some legitimate crystal Aztec artifacts. Then they used scanning electron microscopy to study the surface of both real and suspect crystal objects.

Surface of the crystal objects: Irregular in legitimate artifacts (left) and rotary wheel made fakes (right).

Surface of the crystal objects: Irregular in legitimate artifacts (left) and rotary wheel made fakes (right).

Turns out that the surface of the real artifacts have irregular etch marks, a sign that the pieces were carved with hand-held tools. The suspect skulls have a patterned surface, a sign they were made with rotary wheel tools and hard abrasives.

“Rotary cutting wheels were not introduced to stone workshops in Mexico until after the Spanish conquest of Mexico in 1521. The skulls therefore cannot be of Aztec manufacture.”

Awesomely, the museum researchers noticed a small deposit of something unknown in the Smithsonian’s skull. Using x-ray diffraction they discovered that the deposit was silicon carbide, a synthetic abrasive only used in stone carving workshops starting from the mid 20th century onward. The Smithsonian artifact had probably been made shortly before it was sent anonymously to the museum.

The researchers also had a closer look at the British Museum’s fake skull and discovered  green, worm-like inclusions in the rock.

“Using Raman spectroscopy, the green inclusions were shown to be an iron-rich chlorite. These minerals are found in mesothermal metamorphic greenstone environments. Sources of this type are not found in Mexico or within the ancient Mexican trade network.” In fact, they are typical in rock crystal from Brazil or Madagascar.

Wham bam.

Interestingly, the report alludes to the fact that there are other crystal skulls around: “An increasing number of large and small quartz skulls have become known, particularly in recent decades.” Perhaps the owners should take a closer look at the surface etching of these skulls…

Author: Sarah Everts

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2 Comments

  1. This is great! I know that modern forgeries can be a lot trickier to spot, but I still love the way analytical techniques can be used to conclusively point out fakes. Such a satisfying way to prove the importance of the relationship between cultural property and science!

  2. I love the disparate techniques required to solve this mystery. It really is a sister of forensic science, though in less macabre situations. Err, skull notwithstanding.