Great Seal analyzed at URI laboratory

10/30/07 - A team of scientists and news correspondents crowded into a small laboratory last Friday morning to analyze a rare silver-coated artifact that could be a double of one of the Great Seals of the United States.However, the tests proved to be inconclusive, as the only basis for comparison is at Mt. Vernon in Virginia.

Portsmouth antiques dealer and amateur historian John Pierce bought the seal at a yard sale. He found the die, or stamp, at a Tiverton estate sale last March and if authentic, the seal would be a prototype of the first seal of the president, which was owned by George Washington.

"We were driving through the forest in the Tiverton area and there was a yard sale sign so we pulled up," said Pierce. "There was a box with a few other silver plates and I saw this disc come out [of the box] and I just grabbed it. The guy said 'I don't know what that is, but it's five bucks.'"

When Pierce examined the die further, he realized that it was in fact the Seal of the United States and not a coin as he originally thought. He found it strange because no other seal he could think of had an eagle with a bundle of arrows in the right talon.

"I saw this and thought 'oh this is wrong, it's just a paper-weight and not an original die,' until I ran across this reference of a very obscure book called "The Eagle and the Shield,'" he said.

Pierce said it was at the very last chapter that he found an artist's rendering of the very presidential die he had. The illustration was of the Dorrsett Die, named after the family that held onto and protected it for more than a century. It is now believed to have been a gift to Washington during his presidency sometime around 1789, but was sold to one of Washington's cousins for $6, ironically enough.

Dennis Hilliard, the director of the Rhode Island State Crime Laboratory, electrical materials engineer Michael Platek and URI engineering professor Otto Gregory administered the analysis of the die. They used a $250,000 electron microscope, which uses X-rays to see inside the die and determine the components of its core at 100,000 times magnification.

"This is an environmental scanning electron microscope which is used for non-destructive testing, which means we can look at the die without changing or altering it," Gregory said. "When the electron beam interacts with the sample, it gives off characteristic X-rays and we analyze the X-rays on a spectra-graph."

Through a microscopic hole in the silver-plating of the die, the scientists could see directly into the core. The most common metal used for cores at the time was bronze, so they believed that if the Pierce's die's core turned out to be the same then it would be a big step in authenticating the piece.

"We were looking for bronze, which is a copper-tin alloy and we found an area in which the silver coating has been chipped away to expose the base metal underneath without any interference," said Hilliard. "That base material appears to be a lead alloy, not bronze."

This does not however discount the Pierce die as a fake, Hilliard said, because the original die's core composition is not known at this time, and he is planning at some point to perform the same analysis with the Dorsett piece.