When it comes to ancient Jerusalem, it appears there was silver in them thar hills.

A recently released study conducted by Bar-Ilan University and the Lawrence Berkeley National Laboratory shows that pottery from the time of the Second Temple (around the first century BCE) contains high concentrations of silver.

This doesn’t mean prospectors should rush out to claim a silver mine on Ben Yehuda Street. However, project researchers say high silver values in the pottery suggest the ancient capital was a very wealthy city indeed.

“The high abundances were not due to an experimental flaw. They were real,” says Frank Asaro, a nuclear chemist from Berkeley Labs who worked on the project. “Jerusalem was a city ripe for plunder. We thought this might be [another] indication of the wealth of the area.”

Asaro’s partner was David Adan-Bayewitz, a professor of archeology at Bar-Ilan University in Ramat Gan. Together, over a 20-year period, the two studied 1,200 vessels from several excavation sites across Israel.

They then ground tiny pieces of potsherd into powder and analyzed the material with a process Asaro helped develop known as neutron activation analysis.

The results showed high silver concentrations from the Jerusalem sites. Since silver is not routinely found in clay pottery, the scientists could only wonder at how it got there.

“We made two deductions,” says Asaro. “One related to human activities, the other, that the silver was moved by groundwater. At that time in Jerusalem, there would be a tremendous influx of people coming in to pay taxes, and some paid in pieces of silver.”

Somehow, with all that silver floating around, enough molecules flaked off to make their way into the clay. It took Asaro’s instruments, reading the tiniest parts per million, to detect it thousands of years later.

Jerusalem’s ancient silver boom was short lived. The Romans destroyed the Second Temple in the first century CE. “We have some of their pottery from a few hundred years later,” says Asaro. “It did not have any of the silver anomalies.”

At 79, Asaro still loves his work, and his archaeological research continues. In fact, he and his colleagues have written several papers on the subject published in scientific journals, including a recent paper in “Archeometry,” the People magazine for archaeologists.

Apparently, that one really hit the jackpot.

Says Asaro: “We crammed a lot of stuff into that paper.”