Quote:
Originally Posted by barrysloate
Steve- you should be able to detect an added mintmark pretty easily. But a laser that simply smoothed light scratches out of the surface of a coin could be a whole lot tougher.
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Yes, it's harder. But I read an article on how they detect it, and it's a matter of the flow of the metal being different between coining where the flow is generally out from the center, and the laser which just melts the high spots.
Under 10x it might not be visible, but much higher magnification makes the flow lines and grain structure of the metal visible.
Still pretty worrisome for anyone buying an expensive coin that's not graded, or that was graded earlier.
And yes, the added mintmark was pretty easy to spot. Typical solder job with the coin roughed up a bit in that area then polished and slightly re-tarnished. It was a Half too, a 1921-D. Not high grade, Maybe fine.
Steve B