The Multi Date Penny: A Conservationist’s Guide to Preservation

The Multi Date Penny: A Conservationist’s Guide to Preservation

I’ve seen too many valuable pieces ruined by improper cleaning or storage. Here is how to keep this safe for the next generation.

Understanding Your Find

The penny you’ve discovered is a fascinating example of what numismatists call a “struck through grease” error. This occurs when minting equipment is lubricated and some of that grease or debris becomes trapped in the die, preventing the metal from flowing properly into certain areas of the design. What makes your find particularly interesting is the optical illusion created by the grease-filled areas, which can make the date appear to show multiple years depending on the viewing angle and lighting conditions.

Your coin appears to be a 1992-D Lincoln cent with a “close AM” reverse, which is already a notable variety. The “close AM” refers to the spacing between the letters “A” and “M” in “AMERICA” on the reverse side – in 1992, the Philadelphia Mint briefly switched to a design where these letters were nearly touching, while the Denver Mint continued using the traditional “wide AM” design. Finding a 1992-D with the close AM reverse is already a semi-key date for modern Lincoln cent collectors.

The Science of Toning and Oxidation

One of the most critical aspects of coin preservation is understanding toning and oxidation. Toning occurs naturally when copper coins are exposed to sulfur compounds in the air, creating a protective layer of copper oxide. This layer can develop beautiful colors ranging from reds and oranges to blues and purples, and in many cases, original toning actually increases a coin’s value.

The toning process is essentially a form of controlled oxidation. When copper oxidizes, it forms compounds like cuprite (red), tenorite (black), and various copper sulfides (blue, green, purple). These compounds create a barrier that actually protects the underlying metal from further corrosion. However, improper cleaning can remove this protective layer, exposing fresh copper to the environment and accelerating deterioration.

PVC Damage: The Silent Killer

Perhaps the most insidious threat to coin preservation is PVC (polyvinyl chloride) damage. Many inexpensive coin holders, flips, and storage pages contain PVC as a plasticizer. Over time, especially in warm or humid conditions, PVC can break down and release acidic gases that create a green, slimy residue on coins. This damage is irreversible and can significantly reduce a coin’s value.

Look for signs of PVC damage: a cloudy or hazy appearance on the coin’s surface, green deposits in the recesses of the design, or a sticky feel when touched. If you suspect PVC contamination, the coin should be removed from the affected holder immediately and stored in archival-quality materials.

Proper Holders and Storage Solutions

The right storage solution is crucial for preserving your multi-date penny. For long-term storage, consider these options ranked by protection level:

• Archival-quality flips: Made from polyester, polyethylene, or Mylar, these are inert and will not react with your coin. Avoid vinyl or PVC-containing products.
• Air-tite holders: These provide excellent protection against physical damage and environmental factors. They’re particularly good for coins you want to display while keeping them safe.
• Slabbed storage: For particularly valuable coins, professional grading and encapsulation provides the ultimate protection. The coin is sealed in a hard plastic case with a labeled insert.
• Temperature and humidity control: Store your collection in a cool, dry place away from direct sunlight. Ideal conditions are around 70°F (21°C) with 40-50% relative humidity.

To Clean or Not to Clean: The Conservationist’s Perspective

This is perhaps the most controversial topic in coin collecting. As a conservationist, my emphatic answer is: do not clean your coins unless absolutely necessary. Here’s why:

Cleaning removes the natural patina that develops on copper coins over time. This patina, while it might look dirty to the untrained eye, is actually a protective layer that prevents further corrosion. More importantly, cleaning can create microscopic scratches that are visible under magnification and significantly reduce a coin’s grade and value.

Even gentle cleaning methods like soaking in distilled water or using mild soap can alter the coin’s surface. The only exception might be removing harmful substances like PVC residue or organic matter, and even then, this should be done with extreme caution by experienced conservators.

Your multi-date penny, with its struck through grease error and potential close AM variety, is exactly the type of coin that benefits from being left in its original condition. The grease-filled areas, while making the date appear unusual, are part of the coin’s unique character and history.

Handling and Examination Best Practices

Proper handling is essential for preservation. Always hold coins by their edges, never touching the flat surfaces with your fingers. The oils and acids on human skin can cause tarnishing and leave permanent fingerprints. Wear clean, cotton gloves when examining your coins, and work on a soft, clean surface.

When examining your multi-date penny, use proper lighting and magnification. A good quality magnifying glass (10x power is usually sufficient) and a bright, white light source will help you see the details without having to handle the coin excessively. Take photographs for documentation rather than constantly re-examining the physical coin.

Documenting and Valuing Your Find

While struck through grease errors are relatively common and typically don’t command high premiums, the combination of factors in your coin – the 1992-D close AM variety, the die cracks, and the missing letter – creates a unique piece with potential interest to specialized collectors.

Document your find thoroughly. Take clear, well-lit photographs from multiple angles. Note the coin’s weight (modern Lincoln cents should weigh approximately 2.5 grams), diameter (19.05mm), and any other distinguishing characteristics. This documentation will be valuable if you ever decide to sell or have the coin professionally graded.

Consider having your coin authenticated by a reputable third-party grading service like PCGS or NGC. They can confirm whether you have the rare close AM variety and encapsulate the coin in a protective holder with an official attribution.

Preservation for Future Generations

The true value of a coin like this extends beyond its monetary worth. It represents a moment in minting history, a unique error that will never be exactly repeated. By preserving it properly, you’re not just protecting an investment – you’re safeguarding a piece of numismatic history.

Consider creating a simple display or storage system that protects the coin while allowing you to appreciate it. A small, archival-quality box with a clear top, stored in a temperature-controlled environment, would be ideal. Include a note about how you found the coin and its significance for future collectors or family members who might inherit it.

Remember that the goal of conservation is not to make a coin look “perfect” or “new,” but to preserve its current state and prevent further deterioration. Your multi-date penny, with all its quirks and errors, is exactly as it should be – a genuine artifact of the minting process that deserves to be preserved in its found condition.

Conclusion

The multi-date penny you’ve discovered is more than just a curiosity – it’s a testament to the complexities of the minting process and the unique variations that make coin collecting so fascinating. By following proper preservation techniques, you can ensure that this piece of numismatic history remains intact for future generations to study and appreciate.

Whether your coin turns out to be a common error or a rare variety worth significant money, the most important thing is that you’ve taken an interest in preserving it. In a world where many historical artifacts are lost to neglect or improper care, your commitment to conservation ensures that this small piece of American history will survive to tell its story for years to come.

Happy collecting, and may your passion for preservation inspire others to protect our shared numismatic heritage.

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