Now days you hear about different coin grades.  You may even ask coins dealers or shops about this different terminology.  This question usually comes to light when speaking about how a coins are graded of just simply how it looks to the eye.  More importantly, this nomenclature is often used in the advertising of the coins, whether it be in printed articles of even online sales. In summary, I was given many different opinions to this question.  Is there a guide somewhere?

A recent article written by Joshua McMorrow-Hernandez for PCGS in March of 2022 sums this question very well.  It is as follows: 

Many coin collectors may be familiar with or have at least heard of the terms “BU,” “Choice BU,” “Select BU,” “Gem BU,” and “Superb BU,” but what do these words mean and what do they have to do with coin grading?

This 1957 Franklin Half Dollar grades PCGS M63 and may equate to what many refer to as “Choice BU” in typical coin dealer parlance. Courtesy of PCGS.

The BU-based grades are abbreviated forms of the larger “Brilliant Uncirculated” grade descriptor and are generic terms that broadly define uncirculated coins on the basis of overall eye appeal. The adjectives tacked onto the lead position of some BU grades – “Choice,” “Gem,” and Superb” – generally refer to increasing levels of eye appeal and other alluring factors.

While we at PCGS generally use the term “Mint State” accompanied with a corresponding Sheldon grading number to declare the grades of uncirculated coins encapsulated within our holders, it is nevertheless helpful to understand where along the numerical grading spectrum the various BU grades fall and what they mean.

Bear in mind, BU grades are open for interpretation by both the collector and dealer and are not precise – one reason we avoid such grading nomenclature when assigning official grades. They are presented below not as an official translation of PCGS grading standards but rather as a general observation of how the bulk of the marketplace usually defines BU grades.

• BU, Brilliant Uncirculated – This grading term usually refers to coins in the range of MS60 through MS62, representing an example that is uncirculated but on the lower end of eye appeal. There may be some unsightly, even heavy nicks, scratches, and other imperfections, though luster is often present on an uncirculated coin marketed under the “BU” banner – a typical catchall grade descriptor for rougher uncirculated coins a dealer may break out from rolls or uncirculated sets and individually sell as singles.

• Choice BU, Choice Brilliant Uncirculated – Choice BU was traditionally assigned by collectors and dealers to refer to coins grading approximately MS63, though many have used the same adjectival grade to describe pieces that would otherwise grade MS64. Choice BU coins have cleaner (not cleaned) surfaces than a typical BU, usually free of the heavy marks and other surface flaws expected on the lower-end uncirculated coins.

• Select BU, Select Brilliant Uncirculated – The Select BU nomenclature is usually reserved for describing coins that might grade MS64, though this is not a hard-and-fast rule. The “Select” descriptor is usually viewed as classifying a coin that is better in grade and eye appeal than a Choice BU but not as nice or well struck as a Gem BU, the latter representing one of the most important grade descriptors among major dealers and mass promoters, especially those who deal in bulk orders.

• Gem BU, Gem Brilliant Uncirculated – A coin designated Gem BU should typically be a handsome uncirculated specimen with few heavy marks or other detractions. Many collectors and dealers would both buy and sell Gem BUs on the basis that the coin would grade MS65, though, again, Gem BU is not a precise numerical grade and is thus open to the interpretation of the buyer and seller. MS65 is a landmark uncirculated grade for many coins and anyone buying a coin graded Gem BU should be particularly attuned that they are getting what they think – or assume – they are getting. The PCGS definition of MS65 is as follows: “[The coin] will have some marks and/or abrasions, but they will be minor. The strike must be above average, and luster and eye appeal must be good.”

• Superb BU, Superb Brilliant Uncirculated – A coin described as Brilliant Uncirculated is usually equivalent to a coin bearing a grade of MS66 or even MS67 and should represent a best-of-the-best coin. As we’ve already discussed, be wary buying coins with this or any other of the above BU-based descriptors, as all are open to one’s own interpretation. Certainly, a coin described as Superb BU should offer outstanding surfaces and might be expected to have few if any significant imperfections immediately evident to the naked eye. As with purchasing any coin given a generic grade such as BU, make sure you know what you’re buying.

The information provided above is offered to help collectors navigate their way around a coin shop, magazine advertisement, online offer, or other instances where generic grading may be applied to uncirculated coins. However, PCGS normally avoids generic grading nomenclature in favor of more precise numerical grades with rigid definitions and applications, and this article should not be interpreted as an endorsement of such grading terminology. Nevertheless, we hope you will find this unofficial rundown on BU grading terminology helpful in your coin-collecting pursuits.

Source: What Are BU, Choice BU, Select BU, Gem BU, and Superb BU Coins?