I recently purchased a NGC slabbed svdb. Its absolutely gorgeous! Only problem is that there is a small area of concern underneath Lincolns bust. It can only reallly be viewed under magnification, and it turns black/dark greenish depending on light. I would post a picture, but my camera is pathetic. I plan to take it to a dealer to look at. I have full return priveleges, so no big deal if it is. Anyways, I began looking at other keydate slabbed Lincolns on heritage. I am simply AMAZED at how many I've seen that have "green" on them in problem free top tier slabs?? I'm actually wondering if my eyes are ok.....Here are some examples, please view the closeup pictures. http://coins.ha.com/common/view_item.php?Sale_No=28061&Lot_No=21018 http://coins.ha.com/common/view_item.php?Sale_No=1108&Lot_No=1015 http://coins.ha.com/common/view_item.php?Sale_No=68032&Lot_No=62014#Photo So I need a sanity check. Is what I'm seeing on these coins actual PVC or corrosion?? or is it just dirt and crust that looks kind of greenish? thanks for your inputs, John
I am sorry, but you are going to have to be a little more specific. I looked at all 3, but can see nothing greenish. I even played with the second one on photoshop, but saw not a hint of green.
Ok. Maybe my eyes are bad or my monitor is off. This would be good to know. Do you see green around the wheat stalks? This is the first coin in the link I believe.
It looks like most any other circulated coin I have. There is some dirt there, but that is normal. It is black, not green. I should note that my monitor is not as sharp as it should (used to) be. However, so far as I know, the colors are true.
I see a little green, don't know if its corrosion, pvc or dirt. The back of that s VDB looks nice. post the front!!
Johnny, There is nothing wrong with your eyes. As I stated in a previous post, PCGS and NGC have slabbed problem coins for years. Everything from bent, verdigris, to graffitti. In this day of Numismatics, perception is everything and the promotional efforts by the "top tier slabs" conveniently leave out certain facts. Take it from those who started TPG's. They don't buy sight unseen because they know what the score is so neither should ayone else. One word of advice. If you are not happy with the coin, return it even if it's problem free. You don't need to wonder if your coin has problems every time you look at it.
I see Green on the Wheat Stalks I can see some green on the wheat stalks, and the black spots can also be an earlier stage of oxidation. The problem is if you did not have the coin slabbed by NGC how do you know what it looked like at the time of slabbing/ grading? You don't. If you keep a copper coin that has begun the oxidation process your only recourse in the future is to send it back to NGC if you believe the grade has actually went down since it's time in the holder. If your coin is XF 45, and you believe that grade is no longer acurate, NGC will pay you the difference if they aggree. PCGS will buy your coin back from you. (NGC may do this as well in some circumstances) The good news is that the oxidation should not be able to continue in a sonically sealed holder. If new atmosphere cannot enter the space your coin inhabits then the process has a limited ability to destroy your coin. If there is a chemical of some type on the coin causing any type of process to take place (doubtfull), who knows what could happen to it. Either way NGC has garunteed the grade. The smartest option would be to opt for purchasing a problem free coin. Something without dirt, signs of oxidation, or other issues. Whenever you are dealing with copper this is extremely important. When the grading services first started they were reluctant to garuntee copper coinage because issues like this do arise. You probably don't have to worry much with your coin, but it would always be better to have one without small areas of oxidation, or built up residue.
Don't get too amazed.... PCGS and NGC cannot stop the forces of nature. Remember the inscription on the Titanic? "Even God cannot sink this ship." The grading services do thier best to make sure the coin does not have any issues, and then they try to perserve the coin. This is why they garuntee their "GRADE". They do not really garuntee the "COIN". Therfore if the grade comes into question you have the opportunity to make the TPG stand on their word. Personally I would just try to get my money back, and find a coin that you will not regret buying. -FYI on copper oxididation- Initially, bare Cu metal atoms react with air to form the pink oxide, cuprite, Cu2O, which has Cu+1 cations. This gradually oxidizes further to the black oxide, tenorite, CuO, with Cu+2 ions. The black sulfide CuS also sometimes forms. In the presence of moisture, the blackish layer slowly reacts with sulfur dioxide and carbon dioxide from the air to eventually form the patina, which is a mixture of 3 minerals: brochantite, a green, hydrated copper sulfate, Cu4SO4(OH)6 malachite, the green, hydrated copper carbonate Cu2CO3(OH)3 azurite, the blue, hydrated copper carbonate Cu3(CO3)2(OH)2 In these compounds, copper atoms from the metal surface have been fully oxidized into Cu+2 (cupric) ions. The rate of patina formation and the proportion of the components depend upon humidity and the amount of air pollution. In European cities, where sulfur-containing coal has been burned for centuries, brochantite predominates on older copper roofs and statuary. In rural environments elsewhere, malachite may predominate. http://www.copper.org
I see what you are addressing. I don't think it's PVC damage. I go with verdigris. Many forms of "damage" can show up after a coin is slabbed. Verdigris is one. Fingerprints are another.
AHHHH, there is that Verdigris statement again. Note Verdigris is a substance formed from Copper contacting an Acetate. Not as common as one thinks and just a term overly used such as PVC contamination. Green discoloration on anything Copper is basically as noted by rhoggman. Although the amount of Sulfides and Sulfates is also pending on the invironment. Midwest areas where steel mills once flourished is a common place for such reactions but in dryer, none sulfinated coal burning areas, that Sulfating is just not common. Basically what you have is probbaly just normal starting of the Oxydation process and as long as no additional air can get to that coin, no more problems. If you purchase such a coin, make sure you have a return policy. Even so called air tight slabs can leak.
I use the term "verdigris" the way the average person uses it. I use it to describe the "dry" greenish/bluish coloring associated with items that have a high copper content and are exposed to the elements. This means everything from the simpler compounds like Cu<sub>2</sub>O and CuO to the more complex (see rhoggman's post.) Stuff like copper sheathed roofs or statues. The Statue of Liberty is a fine example. I don't use it to describe the "wet" greenish coloring associated with PVC (yes, I'm aware that PVC itself isn't the problem, but it's easier to type PVC and the average collector understands what is intended.) I don't have to know the particulars. I can leave that to NCS. But I DO have to be aware of the implications of each. I'll continue to describe the "green stuff" by those two terms being fully aware that a great simplification is being made. And most people will understand. Hmmmmmmmm, HTML is turned Off which is why my subscript tag didn't work. How does one go about turning HTML On? Or can we?
Thanks guys. I fortunately do have the ability to return the coin. That was important in my decision to buy.The seller seemed really cool about it when I mentioned possibly returning it, and even offered to give me longer than the specified time if needed. There is no doubt I would keep the coin if it turns out not to be corrosion. It is extremely clean rich chocolate color and very uniform throughout. I think it has better eye appeal than most I've seen imo. I'm hoping to get it to a dealer to look at it within the return time.
