N.G.C. Rare Coin Grading Rarity and condition are key elements in establishing the value of a coin.
Rarity is easy to establish, as there is widespread agreement on the rarity of most coins.
Evaluating condition is more of a challenge. As the collector market for coins grew rapidly in the late 1800s and early 1900s, it became apparent that a more precise grading standard was needed. Some coins were simply more fine than others, and some uncirculated coins showed more luster and far fewer marks than others. In 1948, a well-known numismatist by the name of Dr. William Sheldon attempted to standardized coin grading by proposing what is now known as the Sheldon Scale. His scale, which runs from one to 70, was originally devised specifically for large cents, but it is now applied to all series.