I was talking with a friend about my coin collection when i realized how little I knew! Please assist me to answer some basic questions. Thank you When buying a Graded coin from NGC or PCGS the top grade is a 70...what is the lowest grade? The difference between a 68 to a 69 to a 70...is that 1%? is the grading linear or geometric like with earthquakes and hurricanes? What is the relationship between difference between grades? PF /PR means proof MS means what? UNC means uncirculated, but what is the symbol used for a coin from circulation? Are there any additional Basic categories of coins used in grading Thanks
The highest grade is 70 and the lowest is 1, but unless the coin is rare as heck, you probably won't see a really low graded coin from a TPG, IMO. No, it doesn't go by percentages, it goes by amount of wear on a coin. Between MS-60 and MS-70 (11 grades) it is many times subjective, and done best by persons really familiar with grading mint-state coins. MS-60 and above pretty much assume no wear on the coin. MS means Mint State, which is another way of saying uncirculated (no wear). BS is Business Strike, which covers all circulating coins. I don't know of a symbol for circulation. BU is Brilliant Uncirculated, and some use that as a catch-all to say the coin is somewhere between MS-60 and MS-70, but others use it to say the coin should grade about MS-60 to MS-63 or so, CU is Choice Uncirculated, which translates to a mid-state Mint State (say 64-65) and GU is Gem Uncirculated, which translates to a high-state Mint State (66 and above).
I believe the lowest grade is PO1 - Poor. There is no mathematical formula or ratio that can be applied to the difference between each grade. In Mint State (MS) grades, it is based on luster and the number of detracting marks and whether or not those marks are in the prime focal areas. A circulated coin can fall in any of the lower grades from PO1 to AU58. It might be a good idea if you obtain one of the books on grading such as the ANA Grading Standards for United States Coins. The only other categories which might be used are for problem coins which cannot be labeled with a standard alphanumeric grade such as "MS Details" (used by NGC) or "Genuine" (used by PCGS). NGC will identify the reason for the "no grade" with such descriptors as "Improperly Cleaned", "Altered Surfaces", "Artificial Toning", etc. PCGS encodes the reason for their "no grade" in their certification number. Chris
If it helps, the inventor of the 1-70 grading scale based it on relative value. It was for large cents, and it meant a VG-10 was worth $10, while a BU-63 would be worth $63. That is the reason for the numbers. Today because of people chasing condition above everything else it seems, the price differences are no longer true. They are still somewhat true for circulated coins, meaning in many cases an XF is about 4-5 times the price of a good VG coin. Chris
There is no real "relationship. Grading is an art not a science and in the high end Mint State grades it is all a lot of inconsistant subjective opinions. No. Yes they were based on relative values and the numbers established the value not the grade. And the numbers were a multiplying figure to be applied to the value of that coin in the Basal State grade of Poor. If you know the value of that coin in Poor and you had a coin in Fine then your coin would be worth 12 times what the Poor coin was worth. Sheldon thought the ratios that held for the different grades was some kind of natural law rather than a description of what existed at a given moment in time. So when wages changed, and the number of collectors changed the ratios changed as well but Sheldon and later EAC spend years trying to tweak the system to make the old ratios work again. Finally in 1972 EAC scrapped the system. Five years later the ANA stuck the numbers back onto the existing grades and ballyhooed it like it was something new and different. The numbers are almost absolutely meaningless except to the extent that a higher number is supposed to be better than a lower number. They could have used any numbers they wanted, they could have used letters, or any other symbol because what they appended onto the letter grade has no meaning.
