This article exposes what I consider to be a weakness with the About Uncirculated part of the 70-point grading scale and proposes a solution to improve it.
In the previous days of coin collecting, a simple way existed to describe the condition of coins; a coin was either “new” or “used.” This situation was eventually improved when the American Numismatic Association in the 1970s endorsed a system that William H. Sheldon created in 1949. Here it is in a nutshell:
Two fundamental types of coins exist: circulated or Uncirculated. The circulated coins range in grade from 1 to 58, and the Uncirculated coins range in grade from 60 to 70. This article focuses on the About Uncirculated grade range from 50 to 59.
Grade CategoryNumeric Grade
Uncirculated60 to 70
About Uncirculated50 to 59
Extremely Fine40 to 49
Very Fine20 to 39
Fine12 to 19
Very Good8 to 11
Good4 to 7
The coins in the “Uncirculated” category do not exhibit any wear, and range in grade from 60 to 70, with 60 representing a coin with many heavy marks and 70 representing a “perfect” coin with no marks.
The coins in the “About Uncirculated” category have little wear, with an AU-58 coin exhibiting slight wear on the high points of the coin, an AU-55 coin having friction on less than half of the surface, an AU-53 piece with very slight flatness on the high points, and an AU-50 coin with slight flatness on high points and friction wear over most of the surface.
The coins in “Extremely Fine” category have more wear than the About Uncirculated coins, Very Fine coins have yet more wear, and so on down to Poor, which is a coin that is barely recognizable.
The use of the scale to gauge value works fine in the range from Poor (1) to Extremely Fine (45), and also works in the Uncirculated range from 60 to 70. But the scale does not work very well for coins in the About Uncirculated range of 50 to 58.
A fundamental problem with the AU range of the scale is that it does not consider the condition of the coin as is done in the Mint State range. For example, a coin grading AU-58 could have superior Mint luster, a great strike and no visible marks while another coin grading the same AU-58 could have little luster, a weak strike and numerous marks. Obviously the first coin has a higher value than the second one. The problem is that the only thing that AU-58 specifies is that the coin has very little wear.
In another example, a coin with few marks, a strong strike and great luster that grades AU-50 can easily have more value than a coin that grades AU-58 but has marks, an average strike and no luster.
In reality the value of coins in the AU range also overlaps the value of coins in the Mint State range, and a nice AU coin can be worth more than a lower grade MS coin. This occurs when the AU coin has better eye appeal and fewer marks than the Mint State coin.
I believe the AU part of the scale from 50 to 59 should reflect the characteristics in the Mint State part of the scale from 60 to 69. In other words, an AU-50 coin should look a lot like an MS-60 coin, except the AU-50 coin will have slight wear where the MS-60 coin does not. The AU-51 coin should look a lot like an MS-61 coin, except for slight wear, and so on up to an AU-59 coin that would have a great strike, great luster and no visible marks, but with slight wear. This makes better use of the 10 points available in the AU category of the scale, as it provides a better description of the condition of the coins. This more precise grade can then be used to more accurately value coins in the AU range. This should result in some AU prices that exceed some Mint State prices, as is the case in practice.
One more thing: Hundreds of thousands of certified coins rest in holders with the designations AU-50, AU-53, AU-55 and AU-58. If the definition of the AU part of the scale were changed, how could you tell these old coins designated AU-50 (slight flatness on high points) apart from the new designation AU-50 (many marks but slight wear)? To avoid this confusion the AU part of the scale should be renamed to About Mint State (abbreviated AM). The coins in new holders can then be easily identified as having been graded with the new system, for example as AM-50.
Tom Deaux has been an Internet coin dealer for the past 10 years, primarily on eBay (user ID qualitycollectiblecoins). He opened a brick and mortar coin store in Marlton, N.J., in January 2010.