The Sheldon Grading scale, a metric using numeric intervals from 1-70, is the most widely-accepted method for grading coins across the globe. As the industry standard, the Sheldon Grading Scale provides a comprehensive method for classifying the important details about a coin in an abbreviated, easy to understand fashion. It is important to note, that the Sheldon Scale uses two distinctions. The first is an abbreviated letter assignment that designates the purpose for which the coin was struck and the overall condition. The second, is the numeric assignment that provides an assessment of the wear in more detail.
In order to understand the abbreviations used in the Sheldon Scale, it is important to understand that initially, coins are struck either for circulation or for collecting. Coins struck for circulation are designated “Mint State”, while coins struck for collectors are designated “Proof”. In some cases, hybrid or unique coins that fall somewhere between these designations, as designated “Specimen”. Overall, Proof coins are considered the highest quality, as their production is designed to exemplify the highest level of craftmanship, as opposed to the utilitarian intentions for coins struck for currency.
After designating the strike type, coins are then assigned a numeric value during an appraisal. This numeric value is based on the overall condition and wear of the coin, with the highest quality coins of course being the most valuable. A coin with a lower rating has more noticeable wear, while a coin with a higher rating is approaching perfection. For instance, a coin with a grading of 1-10 has extreme wear, with complete blanking in some cases especially in the lower grades. On the other hand, coins with ratings approaching 70 are almost mint perfect condition, with flaws that are small, and in some cases, imperceptible to the human eye.
True “Proof 70” coins are incredibly rare. In order to qualify for this designation, a coin would have to be not only struck with high quality and the intent to serve as a collector’s coin, but it would also have to be preserved and maintained to a high standard. Proof 70 coins have zero post-production imperfections, even at 5x magnification.