All  

Egypt-Tour-October-13-27

Hair rings (top left), a pin (bottom left), necklaces (middle) and a choker (bottom right) were among a total of 26 gold objects from Poliochni on Lemnos examined by the international research team. Source: Christoph Schwall / ÖAI Wien

Treasure Melting Laser Reveals Legacy of Ancient Alchemists

Print

After a handheld laser “melted” into a collection of ancient gold jewelry a team of scientists discovered microbic evidence of an early Bronze Age trade route extending from Anatolia as far as the Indus Valley. Gold from Troy, Poliochni and Ur all had the same origin. But who were these mysterious gold traders?

In 1873 Heinrich Schliemann , an international entrepreneur and antiquities hunter, unearthed a hoard of gold, silver and copper artifacts which he called King Priam's Treasure, after the Homeric King of Troy who ruled around the 13th century BC.

Heinrich Schliemann, limited by his quest for Troy, never dreamed this collection of golden jewelry was in fact worn by a much older Early Bronze Age culture which existed between 2,500 and 2,000 BC. But now a “mobile handheld laser” has “melted” into the treasures, revealing evidence of an ancient gold trade route spanning thousands of miles.

The hole made by the handheld laser which melts in the surface of the gold pieces is only 120 micrometers in diameter. The damage to the gold object can only be seen through an electron microscope. (Curt-Engelhorn-Zentrum Archäometrie gGmbH)

The hole made by the handheld laser which melts in the surface of the gold pieces is only 120 micrometers in diameter. The damage to the gold object can only be seen through an electron microscope. ( Curt-Engelhorn-Zentrum Archäometrie gGmbH )

River Panning, Melting and Blinging

The golden objects from Troy and Poliochni have become the focus of a new study published in the Journal of Archaeological Science . Poliochni, also known as Poliochne, was once a settlement on the Greek island of Lemnos which was just 60 kilometers (37 miles) from Troy. Researcher Dr. Ernst Pernicka, scientific director of the Curt-Engelhorn Center for Archaeometry (CEZA) at the Reiss-Engelhorn Museums in Mannheim, explained that the new study revolved around data gathered from an innovative mobile laser (pLA).

The laser was aimed at the National Archaeological Museum in Athens’ collection of 26 gold objects, that included hair rings and a hair pin, necklaces and a choker. The paper stated that the laser device “melted” into their surfaces. Horrified at all this talk of “melting”? Well don’t be.

The laser only melts a tiny cone about 120 micrometers (microns) in diameter. And for reference, the hairs on your head measure about 70 micrometers, so the damaged parts of the gold artifacts are only visible using an electron microscope.

Taking a Handheld Laser to the Museum

You might be asking why a handheld laser was taken to the museum in Athens and why the artifacts weren’t taken to the laser? That would have been much easier, right? In this case, the museum's necklaces, pendants, earrings and chokers were deemed so precious that nobody wanted to risk causing visible damage to the objects.

After much deliberation, it was decided to employ the mobile handheld laser which only caused “invisible” damage. The samples of gold were then sent for mass spectrometry at the Curt Engelhorn Center for Archaeometry in Mannheim, where another team of scientists examined their chemical compositions, gathering data that might help identify where the gold originally came from.

Dr. Ernst Pernicka (right) and Moritz Numrich working on the laser ablation device in the National Archaeological Museum in Athens. (J. Huber / ÖAI Wien )

Tracking the Origins of the Mysterious Gold People

High concentrations of tin, palladium and platinum were found in the Troy and Poliochni gold samples. This indicated that the gold was “washed from a river in the form of gold dust,” according to the paper.

These samples matched the chemical signatures of the gold artifacts found in the royal tombs in Ur in Mesopotamia (modern-day Iraq), and both were similar to gold from Georgia. The team concluded: “there must have been trade links between these far-flung regions.”

The researchers explained that the trace chemical elements found in Bronze Age gold samples from Troy, Poliochni and Ur “most likely came from Georgia.” While this means the team are getting closer to identifying who these ancient gold dust collectors, jewelry manufacturers and international traders might have been, Pernicka said the new research “has not unequivocally clarified the exact origin of the Troia gold.”

Map of known Bronze Age gold deposits and distribution of a striking earring with four small spirals. (Ch. Schwall & M. Börner / ÖAI Vienna)

Map of known Bronze Age gold deposits and distribution of a striking earring with four small spirals. (Ch. Schwall & M. Börner / ÖAI Vienna )

Electron Tracking Ancient Alchemists

Because no natural gold deposits have ever been found in Mesopotamia (Iraq), archaeologists have always suspected it came from western Anatolia (Turkey). Thanks to their research the team concluded that the gold came from much further afield - somewhere in modern-day Georgia.

Pernicka explained that in the early Bronze Age “strikingly similar objects were used in a large geographical area from the Aegean to the Indus Valley in present-day Pakistan.” This could mean that these ancient gold traders influenced culture, fashion and style across a huge part of the Bronze Age world.

Perhaps soon, the microns of these laser-melted gold artifacts will reveal even deeper data about the geographical origins of the other metals within the gold alloy. And then, with their high-resolution electron mapping, maybe one day soon the researchers will have a river gorge in Georgia to explore, in search of the ancient alchemists.

Top image: Hair rings (top left), a pin (bottom left), necklaces (middle) and a choker (bottom right) were among a total of 26 gold objects from Poliochni on Lemnos examined by the international research team. Source: Christoph Schwall / ÖAI Wien

By Ashley Cowie

Next article