Chemical & Engineering News has posted an interesting article about the famous Aztec crystal skulls. In recent years the skulls have undergone a barrage of tests which have proved them to be modern productions and not 16th century craftsmanship.
So the team took a closer look at the skulls’ surfaces. As a benchmark, they borrowed a legitimate Mesoamerican crystal goblet from the Museum of Oaxacan Cultures, in Mexico. Then they used scanning electron microscopy to compare these surfaces.
It turns out that the surface of the authentic goblet has irregular etch marks, a sign that the pieces were carved with hand-held tools. But the surface of the suspect skulls have regular etch marks, evidence that they were made with rotary wheels and hard abrasives, which appeared only after the Spanish conquest of Mexico, Walsh says.
Looking even closer at the British Museum’s skull, the team discovered green, wormlike inclusions in the rock. Raman spectroscopy revealed that the inclusions were an iron-rich chlorite mineral. Although this kind of trace impurity is found in rock crystal from Brazil or Madagascar, it is not found in Mexican crystal, Walsh says.
Story: Sarah Everts, Chemical & Engineering New | Photo: Wikimedia Commons