I'm well aware of that. But go look up the actual coin in question. You'll not find even 1 example, in any of the various denominations of the design, that have a textured surface on the bust. They are all smooth.
I agree with a few others. It doesn't look corroded to me. Just has uneven toning. The pic with the line of toning across the obverse is more of an eye sore to me. As for the porosity, I don't think you can conclude corrosion from looking at a few other imperfect coins.
I'm with Doug. It looks corroded. Though the general consensus is that the coin is not corroded, and this may well be the truth, but the pits on the check and neck as well as the uneven texture on the right "0" (500) on the reverse side sure gives it the appearance of being corroded.
I had a liberty seated dime that was corroded and silver, but it looked much worse than this one. The dime looked like it was in some dirt. Silver corrodes less than base metal, but it still corrodes if the environment plays it's part. I just have a hard time seeing a mint state coin such as this one being corroded. Usually other signs are evident. I would guess its wear on the die or a slight planchette flaw of some kind
I would agree, but then, I didn't do that. Instead I looked at all the coins I could find of that design in the various denominations and the various dates for the design - before making my comments. I wonder, did anybody else ? Or did they just decide to trust the plastic instead of what their own eyes told them ? You see, that's what the saying - buy the coin, not the slab - means. It means that you completely ignore the plastic and trust your own eyes. And when your eyes see something that does not agree with what the plastic says, you don't start trying to think of excuses or reasons as to why the plastic says what it does - you go searching to try and find out if what your eyes are telling you is correct. And in this case what my eyes saw was corrosion on the surfaces of the bust, exactly like corrosion looked like on a thousand plus other corroded coins I have seen. So after looking at all of the coins I could find, then and only then did I post my comments. My conclusion, the coin is indeed corroded and the plastic is wrong. Now here's couple more pictures of the same design that I looked at, they show smooth surfaces on the bust too. And before somebody tries to tell me that the surfaces are smooth instead of being textured because the coins are worn and polished, both of those coins are graded MS62 by PCGS. But no doubt somebody will try and think up some other excuse because the plastic, well, the plastic just can't "be" wrong
Doug, the king of hyperbole. Both of those offered "example" images are so out of focus that little "evidence" is offered. Believe what you want Doug. Some of us actually still collect coins, and our opinions are based on reality instead of just cruddy pics we can find online. Cheers.
If toning or tarnish on silver coins is a form of corrosion and dipping a coin is part of the TPG's business, then, by all means, this coin should be graded. I'm thinking it was dipped and what came off, came off, leaving behind a porous surface that is not too different from the mint, close-up image @brg5658 presented us with. Lovely coin, nice remnants of natural toning.
Yes, one is unnaturally matte looking, the other is two-tone from being handled and rubbed in the center. That kind of wear could easily flatten out any porosity, frosting or luster.
Let's take a trip to the early 1900's... Here we have a lovely scan with little detail from NGC, notice no porosity... http://www.ngccoin.com/certlookup/index.aspx?CertNumber=4069306-004 ... and here we have a more detailed image of the same coin, notice porosity... http://www.thehappycoin.com/product-p/soldc243.htm I'm sorry, did I forget to mention the CAC it now has, silly me.
If you know anything about coin photos, it's not hard to adjust your perception and understanding. Just a little imagination goes a long way, to search out what the quality of these particular coins was like, back in the early 1900's... NOT POROUS in this image... http://www.ngccoin.com/certlookup/index.aspx?CertNumber=3738920-013 POROUS in this image... SAME COIN! Check out the nose...
Good point, I agree. TPGs are worthless at times. What about the dies being rough? I know I've seen some uncs that looked worn, but it was because of an overused die. This is the case, for example, with most of the Lincoln cents of the 20s, right? Maybe dies don't get corroded so to speak, but maybe the die with this Brazilian coin just wore down in an ugly way
Just about everything, worn dies, rusty dies, grease filled dies, damaged dies, whatever the case may be, they all result in an individual and distinct look on the coins they strike. Once one is familiar enough with all of them they can each be recognized and distinguished. Likewise, when things happen to the coins themselves post strike, those things can also be recognized. In this case, I believe that coin was corroded for that is the look it has. Now some think that couldn't be the case because they believe that the TPGs would not slab corroded coins. But in point of fact they do and they do it rather often, but it does depend on the coin, what coin it is. Early US for example, the TPGs have slabbed many, many, examples of corroded coins. And there are more than a few examples of world coinage where they will do the same thing. These are facts, not opinions. There are many different things that the TPGs have done and will do because it is their policy to do so, even though these things fly in the face of normal numismatic practice. Things like grading coins with wear as MS, or grading coins that are indisputably damaged in one way or another, or bumping grades, or, or, or. And they even make mistakes like slabbing counterfeits because they lack the knowledge to correctly identify them. Bottom line, if you have the knowledge, trust your own eyes more than you trust the TPGs. Buy the coin, not the slab.
Lets add one more little detail for everyone's consideration. Without dragging the TPGs into this, one might also consider the logical and realistic approach to the porous appearance. How is it that both shown examples display a uniform porosity only on the raised effigy. Was the corrosion trained to perfectly and uniformly attack only the bust, up to its perimeter, while leaving all flat areas much smoother and unaffected? Now, some people think that you will not find "1 example, in any of the various denominations of the design, that have a textured surface on the bust". I found one yesterday in just minutes. That would be a fact, not an opinion. Here is another link for your consideration... http://www.pegasusauctions.com/d12-...silver-mint-state-hairline-scratch-under-neck
I am with physics-fan on this one. After many years looking at coins through a stereo scope I would say this coin was struck with dies that had some light rust cleaned off of them before this coin was struck which is not unusual for a mint in a hot and humid climate before the days of air conditioning.
What you say is true. I've seen many corroded coins slabbed by the top two. I saw a Australian large cent around the year 1920 or 30 with green corrosion (which means it's active and already eating through top thin layers of the coin, right?) graded VHF or xf. I have a French five francs around the 1860s that obviously was cleaned at some time and looks porous in the fields, yet it got a xf. And there's all the classic US coins like you mentioned. Let's say your right about this coin above being corroded, which I kinda believe more now. I can see it suffering toning/corrosion (these two are quite the same, depending who says what and how they are used) and then being dipped to remove it, leaving porosity. Wouldn't you still say the corrosion is quite limited and not active? I don't think it should be detailed graded when compared with others that are
Yes, toning can corrode coins once it reaches it's terminal stage, but until it does, it does not. This has been proved time and time again by the millions of toned coins that have been dipped. Once dipped, there is no corrosion visible. A coin that has been corroded will exhibit porosity, a rough textured surface often accompanied by pitting. That is why when a die becomes corroded/rusted what you see on the coins struck by the corroded die are raised bumps of metal. The green corrosion you mentioned is verdigris. It is most often found on copper coins but it is also found on silver coins and even gold coins at times. But verdigris, while it can literally eat away at the the metal of a coin and can cause pitting, it does not always leave a rough textured surface or pitting behind once it has been removed. But the underlying metal may be discolored. That said, yes the TPGs will slab coins that do have small amount of verdigris on them. And verdigris is not always active, it is only active when there is moisture present. And since moisture can be all but eliminated with proper storage a small spot of verdigris or even several of them will just sit there doing no additional harm to the coin. As to the OP's coin, yes I do believe the coin was probably toned almost solid black at one time and then dipped. And yes I do believe that the toning caused the corrosion seen on the bust and very light traces of it seen in the fields. As to whether the remaining dark toning can still cause additional harm, if not stored properly yes it can. But it is the extent of the damage already done that matters, once the surface of a coin, or part of it, has become porous and or pitted then the coin is no longer gradeable for it has been damaged. Are there worse cases ? Yes, of course, many of them. But there are many lesser cases too, and even those are relegated to problem coin status, and by the TPGs also. With the TPGs it all depends on what coin it is. On some coins even the tiniest bit of corrosion puts the coin in a problem coin slab. On other coins, the entire coin can be covered with corrosion and yet it is still slabbed cleanly. And yes there are all sorts of excuses and explanations given for this by the TPGs and those who have a seemingly blind faith their judgement. But since long before the TPGs ever existed it was and still is basic numismatic policy that once corroded, a coin, any coin, is no longer gradeable.
Give up guys, no matter how much more we know about coins that we may actually collect and have seen like this before, Doug will continue to profess his omniscience. You can't teach an old dog new tricks. I could have the provenance of this coin from the day it was struck, its storage records, the catalog history of its sales, etc...and Doug would still insist it is corrosion. My personal experience with actually collecting world coins from this era and region tell me that the preponderance of evidence here does not support a corrosion hypothesis. Some (ok, one) in the thread have lost track of the coin in question, and instead have made it a thread to air their grievances against TPGs.