@KeeptheChange and others. Do you want to kill me with this coin attribution?
1. Lamination is a process of unification of two different materials. In coins production the clad coins are an example of lamination.
2. DELAMINATION which is the normal term for numismatic. Is use short lam, ok is from long time so will be hard to change. delamination mean structural separation of a material (basic in the begin of the billets or planchet rolls how we say here). This separation occur in general in cold rolling under the crystallization temperature point.
3. EXFOLIATION which is the separation of the layer or layers of a laminated material.
We come back to "delamination" which seem for you is the case here. In a case of delamination due to a molecular structural separation you will see very clear under 10x or 20x the material granulation not scratch line like in this coin example. A delamination could have lines due to the mechanical directional rolling, but never straits, parallels, and between will have the molecular granulation.
Now the coins. I work a little bit the photo for the explanation:
A. Red circle show the end of the scratch wit rolled material versus inside the traces. This is what is say moved material.
B. Light blue lines show the direction of the object or rolls who make the marks
C. the yellow circle show that this occur before milling
D. Blue circles and the strait red line show that something crenelated make the scratch.
In my opinion taking in consideration the year of the coins this was happened in the process of heating the billet or roll (at your choice of name) before the round planchet was cut. In time they use direct fire for heating above crystallization and 60 to 100 degrees bellow melting point. Today the use induction which is more temperature stable and adjustable.
The value of the coin? You guys have more experience then me on this. what I know is that : the grade of the coin is not affected by an planchet default, an strike error or variety. the prices could be different .
I do this kind of analyses for 3 US
TPG, 2 CAN, 2 UK, 1 Germany and 1 Italy.
Hope be at your conveniences.
Posted 03/25/2021 05:05 am
