A publication of the Archaeological Institute of America
It may never be possible to prove conclusively that the mask is fake, genuine, or a pastiche; most scholars we queried thought it genuine. While the National Archaeological Museum in Athens has been reluctant to test the mask, there are a number of procedures available to determine authenticity in addition to that outlined by Traill. The simplest and least damaging is X-ray fluorescence, which could reveal whether or not the gold was alloyed with other metals. Minoan and Mycenaean gold, when mined or panned, was typically composed of between five and 30 percent silver. "If the test revealed the mask were pure gold, or if it were alloyed with copper, that would be cause for worry," says Paul Craddock, head of the metals section of the British Museum's Department of Scientific Research. Craddock adds that examination of tool marks on the mask's surface would be fruitless since the "marks look much the same whether they were made in the second century B.C. or 100 years ago."
Two other tests are theoretically possible, but have not yet been tried routinely on ancient gold. The first is laser-ablated inductively coupled mass spectrometry (LA-ICP-MS), which produces a trace-element fingerprint for gold that can be matched with source mines. But, says Craddock, "sourcing ancient gold is a real problem. There were most likely a multitude of small sources for Greek gold, any number of rivers and mines." Nevertheless, the test might provide evidence for authenticity if the mask were shown to contain the same trace elements as other objects found in the tombs. LA-ICP-MS would require a small sample from the mask and other gold objects from the shaft graves. The second test, known as helium dating, has only recently been developed at the State Hermitage Museum in St. Petersburg; the procedure reveals the date a gold piece was last melted by measuring helium produced in the gold during the radioactive decay of the trace elements uranium and thorium.--SPENCER P.M. HARRINGTON