Well I've got a decent PC now, and am able to easily visit more links now. I ran across this one the other day.
http://www.error-ref.com/recurring-...dence-error/It talks about the Die Subsidence error, aka the Sunken Die. It's an error that produces the same raised area errors on coins even though some are from different dies. On some coins it shows on the reverse, others have it on the obverse.
As many of us know, much of our understanding of the cause of different errors is very important in identifying them. Understandably so,the Mint has not always helped us understand their errors. This leaves us with "the most probable cause" route, or the "best theory" which is how we arrive at "this error is thought to be caused by". Fortunately for us, there are people that have dedicated much of their lives to this. Through their hard work and due diligence we owe them a great debt of gratitude for our numismatic knowledge. These people are known as Leading Experts. Mr. Mike Diamond is one of them and the author of the link.
In the link, the mystery seems to be why are there "Die Subsidence errors in the same location well within the die faces"? Another question is why only reverse dies and other times only obverse? Some of the possible answers are because of three heat treamtents, maybe one or more was too rapid, too slow, or interrupted at some point.
I am certainly not an expert nor will I ever be. I can think though, and feel I should contribute wherever I can. It seems to me the answer to the mystery does indeed involve the heat process/s. If the dies were affected the same, they no doubt suffered the same minting error. The heating process that affected them had to occur when the obverse and reverse dies received it separately. This may rule out one or more heating processes. Also, I think a fourth possible problem with the heating process is improper temperature (due to equipment because it recurs) , perhaps something simple as the master heat gauge. In my opinion, I think it's safe to say the cause of the Die Subsidence error is due to an improper heating process.
If you see a flaw in my rationale please advise. All opinions are welcome.
Posted 12/11/2017 2:23 pm
