Coin Basics & Identification

A plain-English guide to doubled dies, off-center strikes, clipped planchets and other coin error types, and what actually affects their value.

Coin varieties are design differences within a date and mint. Learn what they are, how they form, and why collectors care.

Learn the visual clues, textures, and lighting tricks that reveal whether a coin has been cleaned and why it matters for grading.

Proof coins and business strikes are made differently and look different. Here’s how to tell them apart and why it matters.

MS, AU, and XF are coin grading abbreviations describing wear level, from Mint State to Extremely Fine. Here’s what each one signals.

A plain-language guide to the 1-70 Sheldon coin grading scale, how it works, and why grading affects a coin’s condition and desirability.

A plain-language guide to what coin grading measures, how the scale works, and why condition drives value.

Learn where to find the date and mint mark on US coins, what each letter means, and how to read worn or damaged coins.