This is the VAM 14.4 1878 Morgan Dollar. Here is some info about it. http://www.vamworld.com/1878-P+VAM-14.4 Here is my example in an OLD ANACS MS62 holder.
I really haven't found any good explanation of how it happened... was the die just warped before hubbing?
Only one way it could happen, the die was convex. And yes, I suspect that it was made convex before hubbing.
Morgan dies were delibertly convex so the coin field would be basined to a uniform radius. The die could then be polished with a matching tool. That is why we have mirror Morgans which are lacking in the Peace series which did not have an uniform radius.
Part of what you are saying is true, but part is not. Quoted from VAM World - ".....Field has more curvature than any other Morgan dollar and is especially concave near rim. " "....... Its beautiful concave reverse is unique in the series. " There was no "matching tool". If there was, this coin would not have been possible. Coin dies were polished on flat zinc plates. And the basining of the Morgans had nothing to do with them having mirror fields. They were basined slightly, and near the rims, so that the metal would flow better when they were struck. Many coins are basined, not just Morgans. And the reason Peace doillars do not have mirror fields is because they were not designed to have mirror fields. Morgans were.
All die blanks are convex before hubbing, and all dies are also slightly convex when they are put into use. What makes this coin different is that the die is more convex than normal. From the pictures it appears that the coin is most strongly concave around the edges, specifically between the lettering and the edge. Normally to get that effect you would have to grind that curvature into the die face. Doing that though would result in very weak dentilation and weakness in the tops of the letters. The coin does not show that. One thing that could cause it would be if the edge of the die was sinking. But why would the edge of the die sink? When the dies are hubbed it causes work hardening of the die blank. That was why they had to re-anneal the dies to soften them between hubbings. After the final hubbing the die face would be work hardened and it would be hardest in the center of the die and softest around the edges. Normally the die would be then heated and deliberately hardened so as to have an even hardness across the die face. But what would happen if the work hardened die was used without that final hardening? The hardened centers would hold up for awhile but the softer edges of the die would start sinking. This could give you that curvature. The collar would still insure that the expanding planchet still filled the denticals, but that would also cause extra pressure around the edges and enhance the sinking. Now a die like that would not hold up for long so you would expect coins from it to be scarce to rare. That seems to fit with the rarity rating for this variety. The one BIG problem I see with this theory is that I would not expect the sinking to be as even as it appears to be on this coin.
I dunno, only thing that makes sense to me is that the edges were ground down too much before hubbing. We're not talking a great deal here, I mean the distance would even be hard to measure it would be so slight.
Hello, I seem to have a concave 1878 8tf, yet it doesn't have the characteristics of the above coins, i.e. doubling on the stars, numerals, or lettering. For sure it does not lie flat on leveled surfaces. The coin actually spins many rotations when I spin it on several leveled surfaces. I even tried spinning many of my other Morgan's including 2 other 8tf coins. Steve
