The most fundamental skill in error coin collecting is distinguishing genuine mint errors from post-mint damage (PMD). Many coins that look unusual are simply damaged — scratched, bent, corroded, or altered after leaving the mint. Understanding the differences saves you from overpaying for damaged coins and helps you recognize genuine errors when you find them.
Mint errors occur during the manufacturing process — striking, die preparation, or planchet production. They show specific, consistent characteristics related to how coins are made. Post-mint damage occurs after the coin leaves the mint — environmental exposure, mechanical damage, or intentional alteration. Learning to distinguish the two requires understanding what machinery does versus what random forces do.
The distinction between error and damage is the most important value determinant. A genuine doubled die penny is worth many times more than a scratched penny. Learning to make this distinction accurately is the foundation of building a valuable error collection and avoiding costly mistakes.
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Scan NowPost-mint damage (PMD) is any alteration to a coin after it left the mint. This includes scratches, dents, corrosion, environmental toning, being hit by a lawnmower, dryer damage, and intentional modifications.
Genuine doubled die doubling is raised and shows clear separation between the original and doubled images. Machine doubling and damage show flat, shelf-like displacement. The direction and consistency of the doubling also differ.
Usually no. Most bent coins are post-mint damage. However, if a coin was struck on a bent planchet (the bend exists before striking, with design detail conforming to the bend), that would be a genuine error.
Yes. ErrorHunt's AI scanner is trained to identify characteristics associated with genuine mint errors. While no automated system is perfect, it can flag features that warrant closer examination.