2010 proof set-Buchanan Presidential $1 has concentric circles radiating from center to edge of coin. According to a previous post this may be Lathe lines although I am not sure. The difference I see is that these lines cover the entire coin including the devices, although they are much harder to see on the bust. The lines on the fields are visible to the naked eye. Could it possibly be a defective planchet? Have not had a chance to show set to anyone yet. Has anyone else noticed this on their set? This effect would be hard for me to photograph. Any opinions? Any
I,ve got a few of these coin,s but none with the circle effect you our talking about I,am not sure how rare they are but i sure would like to get a hold of some
You may have something unusual in your set. Whether it's worth something or not, is debatable. I have both the base metal and silver proof sets. Neither have any unusual finishes or patterns on the Buchanan dollar. One does have a less than spectacular finish on the obverse field, but no patterns. If you could post a picture, I'd love to see what you are describing.
I would doubt that they're lathe lines on proofs. The dies are highly polished and would think that they're inspected before use. Do the lines look raised or incuse? Is it possible that it's a fingerprint?
Definately not a fingerprint. Having been a machinist, they look similar to what we called chatter. This is what happens when the cutting tool vibrates as it makes the cut. More of a wavy type of look. But they are definately circular covering the entire surface of coin. Lack
Here's another recent thread. Does it look like this one? http://www.cointalk.com/showthread.php?t=148382
Yes it does. After reading that thread I see there was no real answer as to what is was. I did a search for lathe lines on coin talk and it turned up nothing, sorry for the duplicate thread. Lack
