1. Hold and view the coin correctly. This is a common mistake, one made even by seasoned numismatists. Always hold the coin by its edges, between your index finger and thumb. I use the middle finger on my right hand as a safety net should the coin slip out of my grip. Next, and equally important, is to rock the coin back and forth while at the same time turning it in a circular motion that gives the coin a full 45-degree angle. In combination with superior lighting conditions, this technique will enable you to see hairlines and light cleaning that might otherwise go unnoticed.
2. Choose your lighting carefully. Some may disagree, but I say avoid fluorescent light altogether. I prefer a standard desktop or table mounted lamp with a 100-watt bulb, though others on our grading team use a 75-watt bulb. Do not try to save money by purchasing inexpensive bulbs… I’ve found they give off a more yellow light. Less than 75-watts is not adequate unless you are using a special high intensity lamp. Looking at a coin with a halogen light is, to me, like staring into the sun. Generally, keep 12″ to 16″ between the light source and the coin you’re grading. Look at proof coins twice. Once from a distance of 12″ to 16″, and again from 20″ to 22″ to see hairlines with greater ease. Most important, when you find a light source that works for you and delivers a “true” look at the coin, stick with it.
3. Use a quality magnifier, sparingly. Use a glass only when you really need it, unless your vision requires continual magnification to avoid eyestrain. I have three glasses, a Bausch & Lomb 5x slide, a 16x loupe and a Zeiss 24/12. I only pick up a glass if I see something that warrants closer inspection or if it’s a frequently counterfeited or altered coin type. Continual use of a glass can cause one to micro-grade, focusing on minute imperfections that could lead to consistent under-grading. Microscopes are great for authenticating or confirming hidden defects, but I can’t imagine grading with one.
4. Wipe the slate clean with each coin you grade. One of the first lessons you learn as a professional grader is not to let the coin just graded influence the grade you assign to the next. I have no problem assigning a coin an MS68 grade when it was preceded by a lightly cleaned VF35. Likewise, I would not be influenced into grading an MS64 coin MS65 if the coin before it was a fabulous MS67. At NGC, I would frequently find gems among a group of lower quality coins. If you should come upon an exceptional, all-original group of similar coins, I believe it’s OK to do comparative grading to the extent needed to grade the coins consistently. As an NGC Finalizer, I had access to other grader opinions before I would formulate my own, but I almost always chose to come up with my own grade first, then consider the other grades.
5. Your first impression is usually right. In most cases, within 10 seconds of picking up a coin I have an initial opinion. If you are a beginner numismatist you will need to take more time, perhaps as much as a minute to formulate your initial opinion. I’d say my final opinion matches my initial opinion 80% of the time. The initial opinion is the starting point in determining the final grade. If you grade too quickly, you can easily miss something. Spend too much time, and you’ll out-think yourself into an incorrect grade. If this happens, I suggest you put the coin down, then return to it a minute or two later. You’ll be amazed how easily the grade can come to you after doing this and how it can differ from your previous grade!
6. Counterfeit U.S. gold coins never have copper spots. Did I say never? Well, let’s just say almost never. After viewing approximately 2,000,000 U.S. gold coins, I have seen thousands of fakes and exactly one that had a single copper spot. I can’t explain why this is the case, and it doesn’t mean that the fakes will not develop spots, it is simply an observation of mine that hopefully could be of use to you in the future. Even though this is an authentication tip, not a grading tip, I decided to include it here anyway.
7. Always grade the rims and the edges first. I’ve been told that in the past Europeans would actually grade the entire coin based on the condition of the rims and edges (perhaps some still do). While I would never recommend this, I point it out because many modern day numismatists here in the U.S. have consciously or unconsciously opted to omit this part of the grading process completely! While rocking the coin and rotating it, examine the edges for damage to the reeding, corrosion, evidence of mounting, etc. In order to detect rim filing or repair look at the way the light reflects off of the rims for areas that are uneven or have a different color or appearance. I always inspect rims and edges before going on to grade the rest of the coin, and I urge others who do not practice this to start making it a habit. Rim filing and rim repairs can be very deceptive and, unless the light hits the rim at exactly the right angle, you will almost surely not see them. Sometimes rims are deliberately dulled or toned down to conceal problems, so be careful!
8. Factor in various considerations. Eye appeal (or lack thereof) is a big consideration in arriving at a final grade. The problem here is that few can agree on what constitutes positive eye appeal, other than in the case of a magnificently toned or full blazing white coin. Some might even argue over those. I do not believe it is a grading service’s job to screen out (omit) coins for certification solely on the basis of “negative eye appeal”. That said, I do believe an “ugly” but otherwise problem free coin should get what it deserves in the form of a lower grade. Coins with spectacular original toning are highly preserved, miniature works of art that in some cases should be rewarded with a higher grade. Likewise, a blazing white gem with “pop” could be rewarded. NGC and other major grading services do not consider “properly dipped” coins to be “improperly cleaned”, but any type of conservation effort at all is best left to the professionals as value can easily be destroyed rather than enhanced if improper techniques are employed. Next, and equally important, remember to always ask yourself the question: “How is it made?” (Or, “How do they come?”). I think most professionals would agree that one of the things to come out of the evolution of grading is acceptance that you simply cannot grade coins from different time periods and of different mints the same way, even though they may be the same coin type. If you submitted an 1896 “O” Morgan dollar that looked like an MS65 1903 “O”, I’ll bet you would be very disappointed if it came back in an MS65 holder! You would probably also expect an “O” mint $2.50 Liberty to be graded taking the typical weak striking into consideration. Most choice AU Charlotte and Dahlonega gold might only be XF40 if compared to most choice AU “P” or “S” mint gold. So you can see that one simply cannot apply the same grading standard uniformly to all coins without taking these and other factors into consideration.
9. Arrive at a final grade by combining the results of a “hard look” and a “soft look”. If you go back to tip number five you will see where I suggest mentally recording a quick initial opinion and then going on to look more carefully. During the time between determining your initial opinion and arriving at a final grade I recommend first looking at the coin “hard,” that is to closely scrutinize every aspect applying a precise viewing method consistently. At that point, you should have your “technical grade”. Repeat the process without scrutinizing as intensely, perhaps even looking at the coin through the plastic flip to determine what grade the coin will look like in the holder without ultra close scrutiny or magnification. Now, you are able to determine the “soft look” grade of the coin. The concluding step is to combine these two assessments to arrive at a final grade that is accurate without being overly technical. How often does your final grade compare to your initial opinion?
10. You are your own best teacher, and the absolute best resource for learning is right under your nose! I believe the best way to get a grading education is also the simplest way, and it’s free! First, choose the grading service that you believe grades the most consistently day-in and day-out, the one that represents a fair and reasonable market standard. Now, whenever you have the opportunity to view these certified coins, whether at coin shows, auctions, or from your local dealers inventory, ignore the label completely and grade the coin. Resist the temptation to peek at the grade until you have graded the coin yourself. How often does your grade match the certified grade? This can be a fun and challenging game that will definitely sharpen your skills over time. In order to further your grading abilities you must be willing to accept the fact that, in most cases, if you disagree with the grade assigned, it isn’t necessarily that it was misgraded, but more likely that you are unfamiliar with how the grading service grades that particular coin. Sometimes a coin may appear to have an “obvious grade,” and the label may say something different. Believe me, more often than not, there is a reason for it being graded the way it is graded. If your obvious grade is higher, check for hidden minor problems. Does it have a very light wipe that would not exclude it from being certified but that would affect the grade? Does it have a bit too many carbon flecks? Do you get the idea? If your obvious grade is lower than the certified grade, ask yourself why the coin couldn’t be the higher grade. If you’re still convinced it’s graded too high or too low, there is a great probability that you are unfamiliar with the grading services’ standard for that particular coin. You are certainly allowed to disagree, but keep in mind that the grading service may just grade them differently than you would.
– By John Maben, Former NGC Grading Finalizer [ via ]