Does anyone know...

how carbon factors in to third-party grading?

If, according to James Halperin, surface preservation is the most important factor in a coin's grade (40%), and he weights strike, luster and eye appeal as the remaining factors (20% each), and carbon spots are an element of eye appeal, how much weight might be given them by a TPG?

E.g., what would you estimate a large carbon spot in a prime focal area of an otherwise stunning MS Lincoln—say, on his face—do to its overall grade? Drop less than half? Half? One grade? (I'm assuming the answer would depend partly on the coin's proximity to MS70).

I'm not aware of any specific guidelines on this.

 

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depending on how large (and deep) it is then it can do anything from causing a no grade (for environmental damage) to having almost no effect if it is small.

If it is as large as you say then it not only affects eye appeal, but also surface preservation and can take off anywhere from a point or two al the way to making it an MS60 coin (or worse).

Unfortunately without seeing the coin I can't be any more specific than that.

What I do know is that a carbon spot never "gets better" it always stays the same or grows. And if you buy the coin with it then you will focus on the imperfection more and more over time.

The best advice I can offer is steer away from large carbon spots in the focal areas of coins that you intend to keep.

 

There aren't any specific guidelines on it. There's a big general guideline, though. To even begin to get a sense of it, you have to get your head out of the books and put it back on the coin. I tell that to the YNs in my kid's coin club all the time, and they're crackerjacks at knowing how and when to deduct for these kinds of things. All you have to do is think, "eye movement through the coin." Change that carbon spot to a beautiful, bright red, tarnish spot. Do you see it, now? Your eye still doesn't move naturally through the coin but keeps being tugged back to that spot. It's the distracting nature of the spot that affects the grade by throwing off your natural eye movement through the coin. The more the spot stands out, the worse it is. The more it blends in, the better it is. That's an analysis only you can make when offering to buy or sell on the market, but it's the factor you focus on, and you won't go wrong. You'll rather get good at it, the more you do it.

Best I can offer to tell you; hope it helps...

 

I wouldn't be surprised if those "guidelines" are more for public consumption than anything else. It's like their "guidelines" on how they evaluate eye-appealing toning. I wish I had that link for us, but I don't. You've seen it, though, I'm sure.

 

I never buy coins with carbon and am really asking generally and hypothetically—and with respect to TPGs.

Seems that some collectors don't mind it, others avoid it (I'm in this camp) and still others will put up with a small spot or two if the coin is hard to find and otherwise strong.

 

Eye appeal is my no. 1 priority—clearly it's important to you, too—so I'm already very picky—painfully so. I'm actually more curious about what others think about carbon specifically and, as I said, how it might factor in to third-party grading.

And these are specific to carbon? Is this info published in their grading guide?

I just checked their online guide and only see it mentioned indirectly under Environmental Damage.

 

I don't have the PCGS book but have a few others (Making the Grade, e.g.). I'm really not asking about carbon for myself. I was wondering if there were specific published guidelines that could be used as reference. I am also looking for opinions from others about how they might dock a coin for carbon (I don't buy coins with carbon so it's a moot issue for me). E.g., has anyone had the experience of, say, cracking out a coin with carbon spots, sending it to NCS and then having it regraded?

I realize this is hard to talk about hypothetically (as is every other aspect of eye appeal) so my question might not be that answerable. It would be cool to do a side-by-side "quiz" using several coin types, photoshopping out the carbon in the second image of each pair, and seeing how CT members would grade them (but I'm not going to create this quiz ).

Doug, do you have the PCGS book?

 

The use of the term "Carbon " spot probably confuses the novice and they think they really are related to carbon.

They are not.

They are areas of Copper sulfide deposits, ~ Corrosion. Copper sulfides produce a dark brown to black corrosion on the coin surface with Hydrogen sulfide gas being a good source. Storage with vulcanized rubber products such as rubber bands, some shoe soles, toy cars with rubber wheels, etc. This process is what in environmental gases can cause a copper cent to become steel grey and even black over the years. In thin films they can contribute to toning, but the normal corrosion colors of copper are produced by sulfates and carbonates, which are more blue-green in color, but it the same.

Coin doctors often use Hydrogen sulfide gas in a mixture to produce AT effects, but a mix stronger to the sulfide side of the mix usually produces a dark coin that isn't commercially acceptable. IMO.

 

Interesting. I was referring to carbon "visually" but your info makes me think of another question. What gives carbon spots (say, on silver) their distinctive mounded, granular look—as opposed to the way a flat "toning speck" or toning in general looks? Do impurities in the planchet determine the difference?

 

I am under the impression they can be removed. This is based on before and after images they've published in their advertising, among other things. I'm sure, though, it would depend on how deeply bitten the metal is.

This is exactly what I would assume—that, like any other aspect of eye appeal, or grading in general, it would come down to a judgement call based on experience.

You're right, but to be honest, I've checked them both out at a bookstore years ago and just didn't like the small photos. I don't even like the large photos in Making the Grade—and the grade for many types in that book stops at 65 anyway. I've been relying on Heritage's large photos for lots of studying and cross-comparing. Of course, the downside is I don't have the explanatory guidelines the books offer.

Would you mind bothering to quote the passage (or a passage) about spots? If you don't want to bother, don't worry about it.

 

Corrosion isn't usually a single cause unless induced in a lab, so environmental conditions must be considered. The foci of the corrosive action must also be considered. Gaseous agents ( including some paper envelopes)tend to produce thin films ( flat) more related to colored toning--> corrosion. Whereas "bulk" foci such as "sneeze, saliva, perspiration, drops of chemicals, pvc plasticizers , etc. tend to cause more rounded granular corrosion, but they both end up like that if the corrosive process goes far enough.

Not to be gross or insensitive,but body secretions of sulfur compounds from foods consumed have effects sometimes. If someone's breath, or sweat smells strongly of onions, garlic, cabbage, turnips, etc., they are exuding sulfur compounds. Sulfur is high in hair and nail content as well as skin cells, so a thin eyelash, sneeze mucus, or saliva falling on the coin surface, or probably one of the more common sources, Dandruff, can initiate a almost invisible corrosion loci if sealed inside a 2x2 . A coin might move from one collector to another, being exposed to corrosive agents that are different in each situation. There are chemical reactivities of metals that would have to be considered too.

 

I don't know how TPG grading is affected by carbon spots, but I imagine it attempts to reflect the sentiment of the marketplace. I wouldn't buy a coin like this because I don't want to own it. Someone might, but not me. I'm not saying that if it were an 1877 for $500 I wouldn't buy it to flip it...but I wouldn't buy it for my personal collection.

 

Here's a beautiful proof that I was considering...but I just can't stop focusing on the "mole" on Liberty's chin...very distracting! (imo)

 

Great example of what I would consider a deal-breaking spot on an otherwise stunning coin. I'm with you, I could never appreciate this coin because you'd have to ignore the elephant in the room while trying to do so.

 

Thanks for taking the time to dig this up, I really appreciate it. It's exactly what I was wondering about and looking for.

I think this just about sums everything up. And, frankly (and I'm not at all disagreeing with you about the importance of books), it's ultimately why I didn't buy the books we're talking about: because written words are open to interpretation. No matter how detailed PCGS or the ANA defines their guidelines, who determines, e.g., what "minute" spotting is? Books can provide an excellent foundation but, as you say, you have to take the written information and apply it to the experience of looking at actual coins.

I know you know all this, but let me add something else: you said yourself earlier that PCGS doesn't uphold their own guidelines. Things have changed because the market exerts its own force. This is another reason I do my homework on Heritage comparing dozens of coins to one another, cross-referencing as much as I possibly can. (And let me mention that I'm also constantly scrutinizing coins at shows—for learning; I rarely buy—and talking to dealers about them.) If market forces have altered grading standards, then it's the market, not the "true" grade, that is going to determine what a particular coin ultimately sells for. If you want the coin, you have to pay what the market will bear. Of course, I strongly believe that every buyer should have a sense of whether a coin's grade, and therefore its going price, is inflated in any particular market cycle.