Grading and Classification
“Proof” is another key concept in coin grading. A proof coin is one that is struck at least twice with prepared dies and planchets, and under higher-than-normal pressure to ensure a full, sharp strike. Proof coins are scarcer and tend to be more valuable than other rare coins, drawing special attention from investors and collectors. Some proof coins are deemed circulated because they have been held by investors and collectors.
Since rare coin quality varies widely, numismatists use several coin- grading procedures to assign levels of quality to rare coins. The most popular method to use is the American Numismatic Association (ANA) grading scale.
The ANA grading scale divides circulated and uncirculated coins into 24 grades: 13 circulated grades and 11 uncirculated grades. The lowest circulated coin grade is Poor-1, and the highest circulated grade is Very Choice About Uncirculated-58. The lowest uncirculated coin grade is MS-60 (MS is short for “Mint State”), with the highest being MS-70, or a perfect coin.
How Coins are Graded
When a trained, certified numismatist inspects a coin, he or she examines details such as:
- Mint luster
- Placement and depth of bag marks
- Strike strength
- Other factors
An ANA grading can influence a coin’s future value. High-grade coins typically outperform their lower-grade counterparts in terms of investment performance.
Individual organizations exist for the sole purpose of grading coins, the Professional Coin Grading Service (PCGS) or Numismatic Guaranty Corporation (NGC). For a fee, individuals can send a coin in for grading, which will be returned certified, graded, and sealed in a tamper-evident plastic container known as a “slab.”