What would cause this error? It looks like a die gouge except for the area is concaved insted of convexed. With a 10 X loupe you see grinding marks. I found 11 coins with the identical error fresh from bank wrapped mint rolls. http://i9.ebayimg.com/01/i/03/9a/1b/8b_1_b.JPG
I am assuming the area in question is the small dark area in the field above the buffalo. If the area is concave, recessed into the field of the coin, then you are right to conclude that it is not a die gouge. It must have been something between the coin and the die when it was struck, being a struck through coin. If it appears to have grinding marks under 10x magnification, then the grinding marks would have to have been imparted to the coin from the object on the die, or maybe the grinding marks could actually be rolling marks commonly found on coin blanks, especially nickel planchets. If the substance between the die and the planchet during the strike was grease or some other viscous material, then the original surface marks on the planchet would still be visible on the coin. A group of 11 might show evidence of progression, with the grease/object moving, spreading, or diminishing in size between strikes. Or it could be something else altogether. Need a close-up photo to be sure. Probably not worth a ton of money, but certainly interesting. Neat!
If it is a strike through I find it odd that none of it entered part of the buffalo. It is all in the field and up to the edge of the buffalo similar to what a gouge would do except for it is concaved and not convexed. Any chance a raised area on the die could have been ground down for some reason but not all the way?
Any raised area on the die would have to come from the master die that created the die, which ain't gonna happen. If it was only a single piece, you might say that the planchet was defective and maybe a lamination had broken away, but if you have 11 of them that couldn't be it. Sometimes, the struck though object will only appear in the field and not on any adjacent raised devices. Don't know why that happens, but it does. I'd like to get a closer look at one of your pieces. I have a nice 'BIE' type die break on a PA quarter if you'd like to trade...
I understand what you are saying.However,I find it very strange that this error ends where the field and design meet and doesn't extend into the design one bit.How is that possible?The odds of that happening must be a billion to one.What would happen if the Galvano had this error on it would it get transferred to the Master die?
The galvano would be the most perfect image available. Any subsequent reductions would start with the galvano. The error would have been carried to the master hub, the working hubs, master dies, and every working die created. The master die would be the same relief as the coin, so it isn't likely to originate there, unless the master die was struck through something when it was created, but that's incredibly unlikely. Quality control at the mint would make that virtually impossible. It is not too uncommon for debris to attach itself to the field of a die and not affect the devices. Can you see any progression or differences in the anomaly from coin to coin? Can you post a close-up?
"The master die would be the same relief as the coin, so it isn't likely to originate there, unless the master die was struck through something when it was created, but that's incredibly unlikely. Quality control at the mint would make that virtually impossible." Quality control has really been messing up recently especially on proof coins. http://conecaonline.org/image/2004S25cCladFLSpikeMicro.jpg http://conecaonline.org/image/2004S25cCladIowaSpike300px.jpg http://conecaonline.org/image/2002S25cCladTNSpike300px.jpg http://conecaonline.org/image/2003S5cDCRMicro275pix.JPG http://conecaonline.org/image/2003S1cCrackRevRennerimage.jpg http://conecaonline.org/image/2004-SCladIowawithDieCrack600px.jpg http://conecaonline.org/image/2003SSac4thSpikedHeadeBay.jpg http://conecaonline.org/image/2003SSpikedDiamondAK25c.jpg http://conecaonline.org/image/2000S25cMAsilverProofDieCrack.JPG http://conecaonline.org/image/2002S50cAgSpikedHeadV001smaller.jpg http://conecaonline.org/image/2002S5cSpikledHdPrfMicro2.jpg http://conecaonline.org/image/2003SSacDollarSpikeV001300px.jpg http://conecaonline.org/image/2002S10cCladSpikedRtSd.jpg http://conecaonline.org/image/1971S10cPrfDieCrackWhaden3.jpg http://conecaonline.org/image/1976S10cDieCr.jpg
These are pretty cool! Nice group of die cracks on proof coins. Each of these dies were perfect or nearly so when they were created. All of them just wore out and cracked. Quality control at the die making stage was impeccable. Quality control at the coin making stage is a little less impeccable. When dies are stamping coins and fail, it sometimes isn't noticed until a significant number of coins have already been struck. But master dies are constantly inspected and the working dies are also closely inspected before leaving the die making stage. An anomaly like the 'hump' would have been made by a damaged master die and that is highly unlikely, particularly something so visible. On the other hand, it seems lots of doubled dies are created and make it out of the mint. They can be a result of a doubled working die, master die, hub, or just about any stage of die production. Those don't seem to get pulled out of production.
