Crystal skulls are life-sized human skulls carved from clear or milky quartz. Several have been offered as pre-Columbian Mexican antiquities, and they have been the subject of popular books, articles and documentaries. The question of whether any of them are ancient has now been tested on two of the best-known examples, and the results agreed across several lines of evidence.
The test is not a matter of opinion about style. In 2008, scientists at the British Museum and the Smithsonian Institution published a study of tool marks, mineral inclusions and archive records for two skulls. The study is the main source for this article, and it is worth reading what it did and did not examine.
The British Museum skull
The British Museum’s skull is carved from a single block of rock crystal and measures about 15 cm high, 13.5 cm wide and 21 cm deep. The museum bought it from Tiffany & Company in New York in November 1897. Tiffany’s vice president, the mineralogist George Frederick Kunz, wrote to the Keeper of the relevant department recommending the purchase, and he pointed to his own 1890 book. In that book Kunz wrote that the skull had been brought from Mexico by a Spanish officer before the French occupation, sold to an English collector, and at his death passed to the Paris dealer Eugène Boban and then to a Mr. Sisson. Kunz admitted that little was known of its history.
The 2008 paper, by Margaret Sax, Jane Walsh, Ian Freestone, Andrew Rankin and Nigel Meeks, traced the archive trail further. In 1885 Boban opened a shop in Mexico City and displayed the skull as unique in the world, with no details of where it came from or when it was made. Boban and Leopoldo Batres, the government inspector of archaeological monuments, then tried to sell it to the Museo Nacional de México as an ancient Mexican object. The carving was not considered ancient and was assumed to be modern glass from Europe. Batres then denounced Boban, who moved to New York and tried to sell his collection. According to the paper, a New York newspaper reported in December 1886 that the skull had been sold at auction to a Mr. Ellis of Tiffany’s, and archive documents show Tiffany’s Kunz was involved in that purchase. Two years later a Californian businessman, Sisson, bought it; within ten years he was bankrupt and apparently asked Tiffany to find a new buyer. The paper adds that Boban had also been involved in the sale of three other rock crystal skulls, now in the Musée du Quai Branly in Paris.
What the tool marks show
The researchers pressed silicone moulds into small features of the skulls and examined them under a scanning electron microscope. They compared the marks with those on securely dated Mesoamerican objects: a Mixtec rock crystal goblet and a group of Aztec and Mixtec rock crystal beads. Those objects show no evidence of lapidary wheels. They appear to have been worked with stone and wood tools charged with abrasives, a method the paper says is also supported by textual evidence for early colonial Mexican lapidary work.
The skulls were different. Both were carved with rotary wheels. The curved striations and the cuts at the teeth and mouth on the British Museum skull fit wheel-cutting. The paper concludes that the British Museum skull was worked with hard abrasives such as corundum or diamond. On the Smithsonian skull, X-ray diffraction found traces of carborundum, which is silicon carbide, a hard synthetic abrasive first made at the end of the nineteenth century. Bonded carborundum wheels have been available since the mid-twentieth century.
What the stone shows
The team also studied fluid and solid inclusions in the quartz of the British Museum skull using microscopy and Raman spectroscopy. They report that the material formed in a mesothermal metamorphic environment, at conditions equivalent to greenschist facies, and that this suggests quartz from Brazil or Madagascar. Those are regions far outside pre-Columbian trade networks, the authors point out.
The conclusion
Taken together with the 1885 rejection in Mexico City, the authors concluded that the British Museum skull was worked in Europe during the nineteenth century. The larger white quartz skull in the Smithsonian was probably made shortly before it was bought in Mexico City in 1960. They note that large blocks of white quartz were available from deposits in Mexico and the United States. The label text for the skull, as recorded in the description of one of the Commons photographs below, reads “late 19th century AD.”
What this does not cover
- Only two skulls were studied. The 2008 paper examines the British Museum skull and one Smithsonian skull. It does not report tests on every crystal skull in museums or private hands, including the famous skull associated with the Mitchell-Hedges family. This article makes no claim about those.
- The Paris skulls were not studied in this paper. The paper notes that the Musée du Quai Branly holds the other best-known crystal skull, and that Boban was involved in the sale of three rock crystal skulls now there, but its own tests were on the British Museum and Smithsonian objects. We did not open any separate study of the Paris skulls.
- The tests date the carving, not the idea. The paper’s evidence concerns when and how these objects were made, not what any viewer has believed about them since.
- Tool marks are strong evidence, not a signature. The authors compare marks with securely dated Mesoamerican material and with archive records, and the conclusion rests on several lines of evidence together.
The skulls are real objects with real histories, and the history turns out to be a European and American story of dealers, collectors and museums. For other objects whose popular stories outran the evidence, read about the Piri Reis map and the Lycurgus Cup, or browse our guide to archaeology, objects and museum collections.
Common questions
Are crystal skulls ancient?
The two studied in detail in 2008 are not. The British Museum skull was worked in Europe in the nineteenth century, and the Smithsonian skull was probably made shortly before 1960. Other skulls were not tested in that study.
How do scientists know the British Museum crystal skull is not pre-Columbian?
Microscopy showed it was carved with rotary wheels, which securely dated Mesoamerican rock crystal objects do not show. Its quartz probably came from Brazil or Madagascar, and archive records show a Mexican museum rejected it as modern in 1885.
Where did the British Museum get its crystal skull?
It bought the skull from Tiffany & Company in New York in November 1897. The paper’s archive trail runs from the Paris dealer Eugène Boban through a sale reported in 1886 to Tiffany’s, then to a Californian businessman named Sisson, who later asked Tiffany to find a new buyer.
Did the Aztecs carve rock crystal?
Yes. The 2008 study examined a Mixtec rock crystal goblet and Aztec and Mixtec rock crystal beads from secure contexts. They show no evidence of lapidary wheels and were probably worked with stone and wood tools charged with abrasives.
Sources & Further Reading
- Margaret Sax, Jane M. Walsh, Ian C. Freestone, Andrew H. Rankin and Nigel D. Meeks, “The origins of two purportedly pre-Columbian Mexican crystal skulls,” Journal of Archaeological Science 35 (2008), 2751–2760 — the primary scientific study. Source for the provenance trail, tool-mark and abrasive findings, quartz origin and conclusions.
- Wikimedia Commons, “Crystal Skull British Museum 26072013 05.jpg” by Vassil — CC0. The museum label wording comes from the description on the Commons file Crystal Skull at the British Museum.jpg (photograph by Mike Peel, CC BY-SA 4.0).
