what is the earliest dated coin you've seen that was graded MS70? I'm not sure if this has already been asked here, I couldn't find anything.
Can't remember for sure but the last time this question came up I think somebody found a pic of one dated late '50s, but that may have been a Proof. The earliest date I know of for certain was a '63 Proof 70 cent. But that was downgraded to a 69 about a year later.
From https://www.cointalk.com/threads/what-is-the-oldest-coin-graded-ms-70.56665/ There are 4 1961 PR70 dimes and 1 1964 MS70 cent.
thanks for sharing. I guess I didn't look hard enough. There are a lot of interesting things brought up in that post. Based on the theory on entropy, any MS70 coin put into a slab is bound to lose its "perfect" state eventually. Has there ever been any though put into having a slab that was sealed with the coin being in some sort of mineral oil? The lack of air would stop or at least drastically slow oxidation and other processes that could kill a coins surface. I splice high voltage cables, up to 110,000 volt. I see copper cables encased in oil filled paper that is close to 100 years old and it is still as bright red as the day it was made.
OK, but what else is it encased in ? That paper is merely the inner layer. And rather obviously you can't do that with coins. As for the oil issue itself, well somebody thought of that a long, long time ago. There are several commercial products on the market that contain oils and their purpose, their marketed purpose anyway, is to protect coins. Problem is over time they don't do that. On the contrary, they harm coins. With coins the real enemies are the air and moisture. Now you can't stop the air from getting to coins because there is no such thing as an airtight coin holder. And since the air itself contains moisture you can't stop that either. The best you can do is to reduce it as much as possible. And with proper storage you can do that, you can protect coins so that even in your lifetime you will not see any significant changes. Problem is most people either don't want to believe it, or don't want to bother with expending the effort to store coins properly.
Probably the only way to prevent a coin from reacting with moisture is to put it in a chamber, evacuate the air from the chamber, and then refill the chamber with something like argon. Then you'd hope the chamber is impermeable so moisture doesn't try to migrate back in. Sadly this form of protection would cost more than the value of most coins.
You say that the oil ends up harming the coins, do you know how that happens or know of any material online I could read up on it? I'm just curious about the process
I didn't Google it, but I recall an early 60's Jefferson nickel with full steps selling for around 10K some years ago which was shocking that a modern "common" coin such as that fetched such a high price. I don't know what grade it received, whether or not it was a 70, but the grade must have been high.
I believe this is the cable you are talking about - http://www.google.com/patents/US3145258 If you read that you find that even it breaks down to the point that it must eventually be replaced. How it happens is because the oil breaks down, degrades, over a period of time. There a couple of chemist who are members here who can explain to you far better than I. How I know it happens is because I have seen it with my own eyes, and over the years there have been more than a few articles written on the subject. Do I have online links to them ? No, but then that is not at all unusual because few magazines allow links to their copyrighted material except for paying subscribes, nor do they maintain availability of online access to copies of their magazines which are more than a year old or two old. At least most don't. Some do allow you buy online access to old copies though. But unless you have specific information to pin down the exact issue you are looking for, you have little chance of ever finding it. What's more even the TPGs will refuse to grade coins that have been treated with oils or commercial products that contain oils. That is common knowledge and that information is available on their respective websites.
I know that the oils break down. In the case of the cables, the rate of break down has to do with voltages. Our 4kv system has nearly 100 year old untouched cables that, when opened up, have pristine, bright red copper. On the other end of the spectrum is the 110kv system which has to be "burped" fairly often to release the built up gases caused from a much more rapid break down. As far as coin grading and TPG policies, you guys have worlds more knowledge than I do. After a brief search online I couldn't find anything on the topic so I figured I would bring it up. But it seems that the case is closed on this one
