(1) Check the high points for wear.
Even if a grading service certifies a coin as Mint State-63, that doesn’t mean it won’t come back with a lower grade–possibly even AU-58–if you resubmit it. A coin should stand on its own merits; you should buy it for itself and not for the plastic.
Look at the very highest points of the coin. If they’re lighter in color than the rest of the coin, or if you see friction, the coin may not be mint-state; it may be about uncirculated.
Telltale signs of wear are indicated by the color of the high points. On coins made of copper, the high points after friction are dark brown. On coins made of nickel, the high- point color after friction is dark gray. On coins made of silver, the color is dull gray. And on coins made of gold, the high-point color after friction is dull, dark gold.
(2) If it’s ugly, don’t buy it.
Use your common sense. Blotchy toning, obvious scratches and spots which penetrate the surface of a coin are unattractive. And if a coin appears unattractive to you, it probably will appear that way to other people, too. Therefore, you should stay away from it.
Even coins with very high grades–coins which have been certified as 67, 68 or 69 by a major certification service– are subject to personal taste, and you should always rely on yours. Rare-coin grading is subjective, and so is the beauty of coins.
Among the few characteristics which is universally attractive is concentric circle toning. If you observe this on a coin, you should view it as a highly positive feature.
(3) Examine grade-sensitive areas.
Some flaws are more obvious than others. On Morgan silver dollars, for example, a scratch on Miss Liberty’s cheek is immediately apparent because that part of the coin is so smooth and open. By contrast, a scratch in her hair wouldn’t be noticed as readily because it would be camouflaged by the intricate details in that portion of the design.
High, exposed areas such as Miss Liberty’s cheek are said to be “grade-sensitive,” and you should be more hesitant to purchase any coin with an imperfection there–even though that coin may carry a grade of Mint State-65 or Proof-65 or above from PCGS or NGC.
If you have a choice between one coin graded Mint State-66 with a scratch on the cheek and another coin in the same grade without that scratch on the cheek, always opt for the latter. Everything else being equal, it’s always best to purchase coins whose flaws are in non-grade-sensitive areas.
Grade-sensitive areas for all the major U.S. coin series are identified and illustrated–with color grading maps–in an excellent book by James L. Halperin called How to Grade U.S. Coins. To underscore my enthusiasm for this book, I wrote its introduction.
(4) Look beneath the toning.
This is probably the most important point of all. It’s also the easiest way to determine whether a coin has artificial toning.
Toning can cover up a multitude of imperfections – scratches, hairlines, tooling, thumbing and chemical alteration, to cite just a few. Many times, coins with imperfections are artificially re-toned to conceal these flaws. By examining these coins closely under a magnifying glass, you can detect not only the hidden imperfections but also the artificial toning.
(5) Examine every coin under a halogen lamp or a high- intensity pinpoint light source.
When looking beneath the toning of a coin or otherwise searching for imperfections, it’s essential that you use the right kind of lighting. I first pointed this out in an award- winning article published in COINage in 1979. I later elaborated on this in my best-selling book The Coin Collector’s Survival Manual™.
A halogen lamp is especially beneficial when looking at proof coins. It will help you spot hairline scratches, which can detract considerably from a proof coin’s overall grade. A tensor light is adequate for mint-state business-strike coins.
Ordinary light sources such as flood lamps or bare filament lights–the kind commonly used in chandeliers–make coins appear more attractive than they actually are. For that reason, if you’re looking at coins at an auction-lot viewing session, you should always make sure there’s a halogen lamp or a tensor light source nearby.
(6) Resubmit upper-end coins–coins which are high-quality for the grade–and coins graded 67 by PCGS.
You stand a reasonably good chance of getting a higher grade if you resubmit such coins–especially if you acquired them in 1986 and 1987, when the grading services were extremely tough in assigning grades.
As I mentioned earlier, David Hall conceeds that some of PCGS coins graded 67 many years ago might well come back today at a higher grade. The difference in price between a 67 and its 68 counterpart can be tens of thousands of dollars–so this could represent a $20,000 gift for you, just for taking the trouble to crack a coin out of its holder and resubmit it.
(7) “Read” every coin.
This is a point on which I elaborate in the The Coin Collector’s Survival Manual™. Looking at a coin is similar to proofreading a letter. And individuals who possess book knowledge combined with practical experience at buying, selling and trading coins have learned how to look at a coin and size up its flaws rather quickly, just as expert editors have learned how to scan a manuscript for errors and typographical mistakes.
Often, a coin’s imperfections won’t be noticeable at a glance, or even after somewhat closer perusal by an unskilled observer. This may happen, for example, when a coin has one feature so overwhelmingly attractive that it causes you to lose sight of everything else. Let’s say you’re shown a Saint-Gaudens double eagle with blazing golden luster; the luster may be so intense that it causes you to overlook a bump or a ding on the rim, which in turn might cause the coin to be downgraded.
You should learn how to read all the key information on every coin you handle and properly identify all the imperfections. Don’t be dazzled by any one feature of a coin, no matter how attractive it may be, to the point where you miss important details in the “fine print.”
(8) Look for hairlines.
A proof coin with overwhelmingly beautiful toning can be powerfully appealing. And, to the naked eye, its surfaces may appear pristine and original. But even on gorgeous proofs such as this, and even on coins in very high grades, you may very well find hairline scratches–and the number of hairline scratches is a very important element in determining the grade of a proof coin.
Once again, I suggest that you consult The Coin Collector’s Survival Manual™. The book contains excellent photographs illustrating hairlines on a proof coin. These photos, which noted numismatic researcher and author Kenneth E. Bressett was kind enough to provide to me, are the best of their kind I’ve ever seen.
Spotting hairline scratches is easier on brilliant modern proofs–proof Mercury dimes, for example. It’s somewhat more difficult on older coins with heavier toning – say, Liberty Seated half dollars from the 1880s with concentric-circle toning. On coins such as these, the toning may cover the scratches.
(9) Beware of the rub.
Checking for wear on the high points of a coin is relatively easy–and that’s a good thing, since wear, after all, is the single most crucial factor in determining grade. Detecting rub on a coin is considerably more difficult, for rub is far more subtle. It’s also far more hazardous to the health of that coin.
As the term suggests, a “rub” is a small area on a coin–possibly no bigger than a thumbprint (and possibly caused by a thumbprint)–that bears evidence of friction, showing that the coin has been rubbed. The effect of such a rub can be devastating. Suppose you had a gem, pristine, magnificent coin, blazing with luster, and just one time a perspiration- soaked thumb rubbed ever so slightly across its surface. Even if the coin otherwise might have been graded 65, 66 or 67, that rub could knock it all the way down to AU-58.
To identify rub, you need a good, solid tensor or pinpoint-light source, and you have to tilt and rotate the coin under that lighting. You then need to envision a pencil- drawn circle fully formed. If the coin reflects light in a fully circular pattern, it’s probably mint-state. But if it reflects light in a generally circular pattern but the pattern is disturbed in any way, then the coin may have a rub. Using the same analogy, that pencil-drawn circle would have just a couple of segments erased. The Coin Collector’s Survival Manual™ illustrates this with excellent photographs.
(10) Remember that grading standards have changed since the early 1980s.
A lot of people still own coins which they purchased in the early 1980s and which were graded at that time by reputable dealers or by the ANA Certification Service. But many of these people tend to forget–or never even knew–that grading standards have tightened since then and become more consistent.
So there you are…. some tips and a little guidance on coin grading. There will be much much more to read up on as time goes on, we are working hard to add more content and guides every day!