World’s first money pays a visit to ISIS
24 Mar 2026 - Peter Hurrell
They say money makes the world go round. If that’s true, then 2600 years ago the Kingdom of Lydia must have set the ancient world spinning when they invented the world’s first coins.
Made of a naturally occurring alloy of gold and silver called electrum, and barely bigger than a fingernail, these intricately detailed coins are now revealing their secrets to ISIS researchers.
“Muons and neutrons have changed the game for heritage studies,” says Dr George Green, lead researcher and Associate Professor in Classical and Scientific Archaeology, a joint post between ISIS and the University of Oxford. George and his PhD student Alice Main are using the MuX instrument at ISIS to explore how the ancient coins were made and where the electrum came from.
Alice’s PhD is joint between ISIS and Lincoln College, University of Oxford. The coins she is studying came from the collection of the Ashmolean Museum in Oxford. “I’m well-placed at Oxford. There’s the Ashmolean, teaching and support at the university, and we’re just 30 minutes from ISIS,” says Alice. Her PhD relies on an unusual combination of skills, combining both classical archaeology and modern investigative techniques.
The team brought a small selection of coins to ISIS, all dating from around 600 – 500 BC. They included a coin minted the time of the reign of King Croesus, who was famed for his incredible wealth. Croesus ruled over Kingdom of Lydia, in what is modern-day Turkey, from c. 560 to 546 BC. The Croeseid coin is 94% gold, with an intricate depiction of a lion facing a bull. It is one of the first bimetallic series of coins, consisting of both gold and silver coins that share a common design.
Muons and neutrons have changed the game for heritage studies
Dr George Green
"Coins are made to be circulated"
Some of the very earliest coins brought by Alice include Phanes coins; the first coins to carry an inscription, which read “I am the badge of Phanes.”
The Phanes coin Alice brought to ISIS lacks an inscription, although it does possess a stylised stag design common to other Phanes coins and a characteristic stamped design on the reverse. It is very small, a fraction of the size of modern coins, and was likely used for high value transactions between royalty and merchants, or to pay mercenaries.
Using muons, Alice aims to explore how the coins were made and where the original material to make them came from. “Coins are made to be circulated,” Alice explains, making it difficult to pinpoint where the metals used in their production came from initially.
Previously, researchers have used X-ray fluorescence to analyse the elemental composition of the coins, but X-rays only penetrates to a depth of around five microns. To study the innermost layers, George and Alice turned to muons, which have far greater penetrative depth. Muons are also non-destructive, meaning they can be used to study rare, valuable and fragile samples without causing any damage.
“Little is known about the development of Lydian coinage, but muon-based analysis offers a non-destructive opportunity to investigate its precious metal content. MuX is helping us explore if the earliest coinage in the western world emerged from experimental forays by Lydian metalworkers producing highly inconsistent alloys, or if the coinage reflects a confident mastery of gold-working, with a high degree of alloy consistency across most of the coins sampled,” says Alice.
Little is known about the development of Lydian coinage, but muon-based analysis offers a non-destructive opportunity to investigate its precious metal content.
Alice Main
