LEWISBURG — No one had to go deep underground to crack the case of the corroding coins. Simply underground would do.

It was a Lewisburg treasure hunter "” not the state police crime lab in Harrisburg "” who solved the mystery of the peculiar pennies that forced a Milton bank to close three hours early one day last week after the coins burned the fingers of a teller who handled them.

The pennies, David Mensch said, had likely been found in the soil before they were wrapped and processed at Sovereign Bank and a nearby state liquor store. Being underground would change their chemical composition, which could burn the fingers of handlers.

The bank and a state liquor store called police Aug. 11 when they opened wrapped pennies and found some coins stained and crumbling. A bank teller complained of a burning sensation in her fingers after handling the coins and was treated at a Valley hospital.

Police sent several pennies to the state police crime lab, where tests were inconclusive.

But Mensch, of Lewisburg, who sells metal detectors and collects coins, told Milton police Detective Todd Ulrich that the zinc in the coins produced zinc oxide when exposed to water, and that may have caused the skin rash.

According to Mensch, pennies are made of 99.2 percent zinc and 0.8 percent copper. When they are lost and buried in the ground, other compounds in the soil will react with the pennies and produce zinc oxide, which can irritate the skin.

"I think someone must have found these pennies, cleaned them up and wrapped them for the bank," Mensch said.

"I've found many coins, hundreds, that look just like those," he said. "I have a whole jar full of them.

"As soon as I saw the picture in the paper, I knew what it was," Mensch said. "I called the Milton police and explained what they had."

Milton officers came to Mensch's shop, Treasure Hunters, and he showed them a jar full of discolored and disintegrating pennies.

He said when he finds pennies buried in the sand at the shore, they often crumble at the touch.

Ulrich said when he called the state police crime lab and described what Mensch had told him, officials there agreed with the explanation.

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