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Valued Member
83 Posts |
RE: Quote:
dipping is not the only process that causes silver to spot and tarnish "Dipping" does not cause silver coins to tarnish... dipping in a cleaning solution will / may remove tarnish, but in the process can / does damage the surface of the coin - often resulting in bleached out dull-grey appearance. Process that causes silver to tarnish is described in my previous post - it is exposure to environmental elements / contaminants, and in particular with silver indicates the exposure to sulphur. Dipping doesn't "cause" the dark spots, but rather this is remaining tarnish that did not come off of the coin during the dip process - as previously mentioned, anyone who has experience in using dip to clean silver coins can attest to the most likely areas of coin that tarnish remains on - and these are the areas near legend details and edges of portrait. Tarnish generally doesn't just randomly appear in spots on coins - unless, as in many of the cellophane wrap packages for '50s PL sets, there is a pinhole allowing air to get at a specific spot on coin only. The '67 fifty cent coin you have pictured has begun the tarnishing process. If left to continue it will eventually cover the entire surface of coin. Scott's Canadian Coins |
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Valued Member
83 Posts |
Re: Quote:
Trying to bring appearance into grading is an interesting topic. Now you've potentially moved from a technical assessment of a coin based on ware to an individual opinion on how it looks. It's an obvious problem. This is not a novel concept - all graders (should) employ a combination of examining technical details and condition of coin from visual appearance. Check out this grader James Halperin at http://www.coingrading.com/intro1.html He is regarded as one of the tops in the business and is the co-founder of Heritage Coin Galleries and currently represents Heritage Auctions. In his book he describes part of the process, as based on four steps included in the formula that he incorporates into grading: Surface Preservation - presence of marks / imperfections and analysis of impact on potential grade Strike - sharpness or lack of and how this factors into assignment of grade Lustre - difference between a natural sheen and "cleaned" surfaces and how this is reflected in grading process Eye Appeal - "the grading factor about which expert dealers will most often disagree" Scott's Canadian Coins |
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Pillar of the Community
 Canada
1461 Posts |
Yes we know what dipping does Scott. So let me rephrase since you used the areas of tarnish as part of your diagnosis. The problem is that you seem to automatically assume that tarnish spots on coins and more specifically between high and low points on an otherwise tarnish free coin are a result of dipping. What I'm telling you is that's it's not the case. If you're basing your opinion purely on the color of the coin, all I can say is that I photograph with a white LED light that may give it that tone. Some yellow light was added to the 2 last pictures. The 1967 coin you're looking at has never been dipped (Yes I know it for a fact). The reverse of this coin has sat in an open boxed (not mint sealed) 67 set with the exposed obverse being completely 100% dark tone and the reverse as you see it in the picture. The tarnish is caused purely by the environment. I'm not sure that I can add any more value on the grading piece other than I may agree that in grades over MS66 eye appeal may play a factor in grading but ultimately any coin needs to be primarily graded on technical merit.
Edited by TheCoinHunter
10/23/2013 11:59 am
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Moderator
 Canada
10460 Posts |
Your white LED light is excellent for details at the surface (for grading or defects), but it washes out the lustre, just like a flatbed scan. That is why the large cents look so good on iCollector auctions, but are completely different in hand Coin photography, is a heck of a lot harder than coin grading, in my opinion... Check out this thread, where someone used 25 images and constructed an animated GIF to show off the lustre of his Morgan dollar... http://www.cointalk.com/threads/sho...ment.237608/"Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert OppenheimerContent of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_USMy eBay store
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Pillar of the Community
Canada
1461 Posts |
SPP. That is it. Especially copper. I finding mixing white and yellow light works best (the ladder 2 pictures). Too much white makes the coins looked "washed out". I find scanners even in high resolution hide many surface imperfections and that's why they are often used in online sales.
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Valued Member
83 Posts |
Re: Quote:
"in grades over MS66 eye appeal may play a factor in grading but ultimately any coin needs to be primarily graded on technical merit" I guess American Numismatic Association's ( ANA) standards, as well as previous reference to Charltons and a noted top professional in the field, are wrong as well, eh? Here's link to ANA grading standards - where they identify, as has been mentioned before, that properly graded coins will take into consideration both the amount of original lustre present on a coin, as well as "eye appeal". And not just for coins above MS-66, but for ALL coins. Don't bite my finger off, just look where it's pointing to :) http://www.money.org/explore-the-wo...andards.aspx |
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Pillar of the Community
Canada
1461 Posts |
Here is a good example of a dipped coin that exhibits the "milky characteristics" and some tarnish.  Edited by TheCoinHunter
10/26/2013 4:35 pm
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Pillar of the Community
Canada
1461 Posts |
Cross grade below.  Edited by TheCoinHunter
11/15/2013 6:48 pm
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Pillar of the Community
United States
4233 Posts |
Frankly I find this coin attractive in its unattractiveness. Honest aging, nice strike, clean fields, flawless reverse. This MS64 however I'd probably give a pass on, but it might look different in hand - http://www.ebay.com/itm/1948-ICCS-S...em51a1c50393 |
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New Member
42 Posts |
Actual, I make the mistake, it is this one that the guy the coin hunter he like it so much but the other one he just say that it's only MS61, I think that maybe he like his own reflection better, https://goccf.com/t/162902 |
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Pillar of the Community
Canada
1461 Posts |
Gilles. I'm not sure I understand your point. Coins get posted here and opinion is given.
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New Member
42 Posts |
the point it was this that when you were talking about your coin what you thought was higher grade than arguing with everybody, then now when this coin look as nice or better than that one, that now you tell this guy he coin is no more than ms61, it think thats not right,
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Pillar of the Community
Canada
1461 Posts |
This isn't a coin competition Gilles. The argument here was somewhat to do with the fact that Scott thought the coin was dipped. |It was not.
Edited by TheCoinHunter
11/17/2013 11:39 pm
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New Member
42 Posts |
It seem like maybe you just like to argue maybe and don't like so much when some one has differents opinion
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Pillar of the Community
Canada
1461 Posts |
What opinion? The coin was professionally graded. Twice! Some like the look of the coin, others don't. I don't have a problem with that at all. Again, the arguments in this thread (and a couple of others) went far beyond the coin.
Edited by TheCoinHunter
11/18/2013 12:06 am
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Posted 10/22/2013 6:52 pm
