Coin grading: the collector's guide to condition
From Poor to Mint State 70 — understand the Sheldon scale and why one grade point can double a coin's value.
The Sheldon scale and why it matters
The 70-point Sheldon numerical scale is the international standard for grading coins. Originally developed by Dr William Sheldon in the 1940s for large US cents, it was later adopted across all coin series worldwide. The scale divides into broad categories: Poor (P-1) through Fair (F-2) for barely identifiable coins; About Good (AG-3) through Fine (F-15) for circulated coins with visible design elements; Very Fine (VF-20 to VF-35) and Extremely Fine (EF-40, EF-45) for coins with significant detail remaining; About Uncirculated (AU-50 to AU-58) for coins that show only the slightest wear on high points; and Mint State (MS-60 to MS-70) for coins that have never been in circulation. The jump from one major grade tier to the next can mean a large price difference, which is why grading is both an art and a business.
What graders actually examine
Professional graders evaluate five main attributes: strike quality, surface preservation, lustre, eye appeal, and colour (for copper coins). Strike quality reflects how fully the design was pressed into the metal at the time of production — a weak strike leaves soft, shallow detail even on an uncirculated coin, while a full, sharp strike shows crisp relief on every element. Surface preservation accounts for contact marks, hairlines from cleaning, and planchet flaws that occurred before or during striking. Lustre is the reflective quality that mint-fresh coins display — it dulls over time or when a coin is improperly cleaned. Eye appeal is the overall visual impression: a well-struck coin with original lustre and no distracting marks grades higher than a technical equal with an unattractive combination of flaws. For copper coins, colour classification — Red (RD), Red-Brown (RB), or Brown (BN) — can shift value substantially.
The cleaning problem and why it depresses value
Cleaned coins are one of the most common sources of disappointment for new collectors who buy without knowing what to look for. A coin that has been dipped in chemical solution, polished with an abrasive, or wiped with a cloth may look bright and attractive in a photo but will be assigned a 'details grade' by professional services rather than a clean numerical grade. A details-graded coin — marked 'Cleaned' or 'Polished' — typically sells at a significant discount to an original-surface example in the same apparent condition. The test is in the lustre: original luster flows across the surface in cartwheel patterns when you tilt the coin under a single light; a cleaned coin may shine uniformly or show directional hairlines that betray mechanical cleaning. CoinLens flags when a coin's condition notes suggest cleaning, helping you avoid paying full price for a problem coin.
FAQ
What is the difference between MS-63 and MS-65, and does it matter financially?
MS-63 (Choice Uncirculated) coins are mint state but show noticeable contact marks or slightly impaired lustre. MS-65 (Gem Uncirculated) coins have strong eye appeal, above-average strike, and only minor scattered contact marks. For many popular US and world coins, the price gap between MS-63 and MS-65 is not linear — it can be three to five times larger at MS-65 because the population of true gems is much smaller. For common-date coins in lower grades, the difference matters less.
Should I have every coin professionally graded?
Professional grading makes most sense for coins worth more than the grading fee — typically US$30 or more per coin at major services, plus shipping and insurance. For common-date coins in average grades, the cost of submission often exceeds any premium the slab adds. Save professional grading for key dates, high-grade specimens, or any coin you plan to sell at a significant price. For everything else, CoinLens gives you a reference grade and market range without the wait or cost.
What does 'original skin' or 'original toning' mean?
Original toning is the natural colour change that develops on a coin's surface over decades through slow chemical reactions with the environment. On silver coins, toning can range from pale gold to deep blue, purple, and russet — and when evenly distributed and attractively coloured, it can actually add to a coin's value. 'Original skin' refers to the coin's unaltered surface, untouched by cleaning or artificial toning. Collectors prize originality because it demonstrates the coin was preserved naturally. Artificial toning, applied to improve appearance or hide problems, is generally detectable under magnification and reduces value.