7 Critical Mistakes Collectors Make When Identifying Coin Anomalies (And How to Avoid Them)

I’ve been there. That rush when you spot something *off* on a coin—your heart skips. Is it a doubled die? A rare error? Or just a common flaw hiding behind wishful thinking? After years of hunting Lincoln cents and other U.S. coins, I’ve made (and seen) the same seven mistakes more times than I’d like to admit. The good news? They’re avoidable. And avoiding them means you’ll waste less money, time, and hope—and actually find real rarities.

1. Jumping to Conclusions Without Proper Testing

We’ve all done it. You pull a 1982 Lincoln cent from a roll and see a bump near the ear. “Aha! A doubled die!” you declare. But hold on. Most of the time, what looks like doubling is actually a plating blister, die break, or even a surface defect from storage. Excitement is natural—but it’s also the enemy of accuracy.

Warning Signs You’re Jumping the Gun

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• The bump or bulge doesn’t match any known ddo (doubled die obverse) for that year and mint.

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• No doubling appears on nearby elements—like the date, lettering, or hairlines.

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• It feels soft or gives way when gently pressed—this is a red flag.

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• The anomaly is isolated. Real doubling shows up in a pattern, not just one spot.

How to Prevent This Mistake

Simple: **test it first**. Grab a soft cotton Q-tip or a fine plastic toothpick and gently press *around* the anomaly. If it deforms, pops, or feels squishy? That’s not a doubled die. It’s a plating blister or die break—neither of which will hold up at PCGS or NGC. A true doubled die is part of the die itself. It won’t budge.

“If a toothpick flattens it, it’s not a doubled die. It’s time to rethink your submission.” – something I wish I’d known in 2005

Recovery Strategy

Already sent a coin off for grading based on a “rare error” that turned out to be a blister? It happens. Use it as a lesson. Build a **pre-submission checklist**:

• ✅ Pressure test with Q-tip
• ✅ Use at least a 10x loupe (20x is better)

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• ✅ Compare to known varieties (check coppercoins.com or doubleddie.com)

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• ✅ Take high-resolution macro photos before anything else

This isn’t bureaucracy—it’s discipline. And it saves you $50+ per grading fee.

2. Ignoring the “Shape Logic” of Doubling

Doubled dies form when a die gets hubbed multiple times at slightly different angles. The result? A clean, parallel doubling—like a ghost image just offset from the original. But here’s the catch: it’s *mirrored*, not random.

What Not to Do

• Don’t call a blob on Lincoln’s ear a “doubled ear.” If it’s not shaped like the ear—just shifted—it’s not doubling. It’s likely a die crack or metal flow.

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• Stop calling it “earwax” or “swollen eardrum.” Those are jokes. In your notes, be clear: “die break, ear, central.”

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• Don’t ignore the rest of the coin. Real doubling shows up in multiple places—like both the ear and the “LIB” in “LIBERTY.”

How to Fix This in Practice

Do the **Shape Match Test**:

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1. Zoom in under 20x magnification.

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2. Ask: “What design element is being duplicated?”

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3. Check: Is it parallel? Symmetrical? Does it match the direction of known DDOs for that year?

If the shape doesn’t align? It’s not a doubled die. Take the 1999-D Lincoln cent, for example. Known DDOs affect the “AM” in “AMERICA” and the date. A bump in Lincoln’s ear? That’s not one of them.

3. Overlooking Die Breaks and Gasket Damage

Die breaks—those crescent-shaped cracks or “head wounds”—get mistaken for doubling all the time. But they’re not the same. A die break is a **fracture in the die** from fatigue. It leaves jagged, raised metal. A doubled die? That’s a mirrored copy.

Red Flags for Die Breaks

• Jagged, broken edges (not smooth)
• Dark, oxidized lines inside the crack
• “Slugs” or metal pushed out from the die failure
• No doubling anywhere else on the coin

Prevention: The “Crack vs. Copy” Test

Grab your loupe (10x–30x) and a flashlight. Shine the light at an angle and rotate the coin. Watch how the feature reflects light:

• If it mirrors the design and shines like metal → likely doubling
• If it casts dark shadows, has ridges, or looks like torn metal → likely a die break

Recovery Tip

Suspect a die break? Take **multiple macro photos** under directional lighting. Use **focus stacking** to show depth. When submitting, write: “Possible die break—evaluate for error status.” This keeps the coin honest and protects its value.

4. Confusing Plating Blisters with Die Abnormalities

Plating blisters happen when the copper or brass layer separates from the zinc core—common in modern Lincoln cents (post-1982). They’re not mint errors. They’re storage or environmental damage. And they’re not rare.

How to Spot a Plating Blister

• Feels soft or collapses under light pressure
• Only appears on one coin—no others from the same roll show it
• No matching feature on the reverse
• Often surrounded by tiny cracks or greenish oxidation

What Not to Do

• Don’t try to pop it with a needle. That’s damage.

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• Don’t call it a “rare mint anomaly.” It’s not. It’s a post-strike flaw.
• Don’t submit it for high-grade certification. TPGs will slab it as “damaged.”

Recovery Strategy

If you find one, stabilize it:

1. Store in a dry, archival 2×2 flip
2. Minimize handling
3. Note it in your log: “Plating blister, right ear, stable, not for grading”

5. Misusing Humor as Classification

Calling a die break “Lincoln’s earbud error”? Funny at a coin club meeting—maybe. But in your notebook? On a grading submission? No. It confuses new collectors, spreads misinformation, and can get your submission flagged.

Why This Is a Problem

• Beginners think “earwax” is a real variety
• Grading companies may misinterpret or reject your submission
• Your collection looks unprofessional if you ever sell or display it

How to Prevent It

Stick to **standard numismatic terms**:

• Instead of “earwax,” write “die break, obverse, ear, crescent-shaped”
• Instead of “swollen eardrum,” write “plating blister, right ear, central”
• Use official abbreviations: DDO, DDR, DDP

Recovery Tip

Make a **personal taxonomy guide**. List each term you use and link it to a photo or reference. When you find a new coin, you’ll know exactly what to call it—and why.

6. Failing to Hunt for Corroborating Evidence

Found one coin with a weird bump? That’s not enough. Real die varieties are repeatable**. If it’s a true doubled die, you should be able to find at least a few others with the exact same feature.

What You Should Do Instead

1. Search Coppercoins.com and VarietyVista for your coin’s year, mint, and feature.
2. Look for **multiple examples**. If no one else has reported a “central ear bubble” on 1995-D cents, it’s probably not a die.
3. Check past auctions. No results? That’s a clue.

Code Tip: Use a Spreadsheet to Track Findings

Year | Mint | Feature | Location | Doubling? | Die Break? | Plating? | Source
1999 | D   | Ear bump | Center | No        | Yes         | No       | eBay #12345

This keeps your research organized and helps you spot patterns.

7. Ignoring the Risk of Submission Loss

Let’s be real: mail gets lost. Especially in certain areas. Don’t send a $500 coin for grading unless it’s *definitely* worth the risk.

Prevention: The 3-Step Filter

1. Does it pass the pressure test? (→ No? Stop here.)
2. Is it a documented or highly likely undocumented variety? (→ No? Don’t submit.)
3. Will the graded value cover the fee, risk, and opportunity cost? (→ No? Keep it raw.)

If any answer is “no,” **don’t submit**. Protect the coin as-is. A raw coin with a story is still valuable—and it’s yours to keep, no risk.

Conclusion: Prevent Mistakes, Preserve Value

Finding anomalies is one of the most fun parts of coin collecting. But the difference between a real doubled die and a plating blister can be subtle—and costly if you get it wrong. To stay sharp:

• Always test before you assume

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• Ask: “Is it a copy, a crack, or a bubble?”
• Use real terms, not jokes, in your notes
• Verify with multiple sources before submitting
• Only send coins that justify the risk

Collecting isn’t just about the thrill of the find. It’s about building a collection you can trust—one accurate, well-documented coin at a time.

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