When this crystal skull was bought by the British Museum, they thought that it was of Aztec origin, carved before the conquest. Skulls of this type were a fairly popular topic of myth and speculation on the part of Europeans. Sadly for the museum, this skull is definitively a fake because it has the marks of tools the Aztecs did not have access to. This was discovered by using special silicon wax on the tool marks and examining them under a high-powered microscope. It is likely to have been made in the 19th century by Germany or Brazilian craftsmen.