Preserving Your Error Coin Collection: Expert Tips for Long-Term Protection

Introduction: The Critical Importance of Proper 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.

Error coins represent some of the most fascinating and valuable pieces in numismatics. The five exceptional examples shared recently – including a 1984 Lincoln Cent with Huge CUD graded MS65RD, a 1994 Lincoln Cent Struck on Unplated Planchet MS64, a 1970-D Jefferson Nickel Struck Through Retained Copper MS62, a 1973-D Kennedy Half Dollar Double Struck with Second Strike 85 Percent Off Center MS62, and a Lincoln Cent with Full Brockage MS62BN – demonstrate the remarkable diversity and appeal of minting errors. However, their preservation requires specialized knowledge and careful handling to maintain their condition and value for future collectors.

Understanding Toning and Oxidation in Error Coins

Toning occurs naturally on copper and silver coins as they react with sulfur compounds, moisture, and other environmental factors. For error coins, toning can either enhance or detract from their value depending on collector preferences and the specific error type. The 1984 Lincoln Cent with Huge CUD MS65RD shows beautiful red coloration that collectors prize, while the Lincoln Cent with Full Brockage MS62BN exhibits more typical brown toning.

Oxidation is particularly problematic for copper coins like the Lincoln cents in this collection. When exposed to air and moisture, copper develops a patina that can range from attractive to destructive. The 1994 Lincoln Cent Struck on Unplated Planchet is especially vulnerable since the lack of plating means the raw copper is exposed to environmental factors. Proper storage in controlled environments with stable humidity (ideally 40-50%) and temperature (65-75°F) is essential to prevent accelerated oxidation.

For silver coins like the 1973-D Kennedy Half Dollar, toning typically appears as rainbow hues or deep charcoal colors. While some collectors appreciate colorful toning, others prefer pristine white surfaces. The key is preventing environmental damage that creates unsightly spots or corrosion.

PVC Damage: The Silent Destroyer of Coin Collections

Polyvinyl chloride (PVC) represents one of the greatest threats to coin preservation. Many older coin holders, flips, and storage containers contained PVC, which breaks down over time and releases acidic gases. These gases cause a distinctive green, slimy residue to form on coins, permanently damaging their surfaces.

The 1970-D Jefferson Nickel Struck Through Retained Copper MS62 requires particular attention since nickel alloys can be sensitive to chemical damage. Even brief exposure to PVC can compromise the coin’s grade and significantly reduce its value. Modern archival-quality holders are PVC-free, but collectors should carefully examine any older storage materials.

Signs of PVC damage include:

• Greenish residue on coin surfaces
• Cloudy or hazy appearance
• Sticky or slimy texture
• Discoloration around the edges

If PVC damage is suspected, immediate professional conservation may be necessary, though some damage may be irreversible.

Proper Holders and Storage Solutions

The decision to submit these coins to PCGS for slabbing demonstrates excellent preservation practice. Professional grading and encapsulation provides multiple benefits:

The 1984 Lincoln Cent with Huge CUD MS65RD, now in its protective slab, will maintain its pristine red coloration and MS65 grade for decades, shielded from environmental factors that could degrade its condition.

For coins awaiting professional grading or those you prefer to keep ungraded, several storage options exist:

Archival-Quality Coin Flips

Made from inert materials like Mylar or polyethylene, these holders provide excellent short-term storage without chemical interaction. They allow you to view both sides of the coin while protecting it from fingerprints and environmental exposure.

Airtight Containers

For particularly valuable pieces like the 1973-D Kennedy Half Dollar Double Struck, airtight containers with silica gel packets help control humidity. These are ideal for coins with sensitive toning or those prone to oxidation.

Temperature-Controlled Storage

Long-term storage in a climate-controlled environment prevents the temperature fluctuations that can cause condensation and accelerate toning or corrosion. Avoid basements, attics, or areas near exterior walls where temperature and humidity vary significantly.

To Clean or Not to Clean: The Preservation Dilemma

This question generates intense debate in numismatic circles, but for error coins, the answer is almost universally “do not clean.” The 1994 Lincoln Cent Struck on Unplated Planchet MS64, for example, derives significant value from its original mint state appearance. Cleaning would remove the natural patina and potentially damage the delicate surfaces, reducing both grade and value.

Professional conservation differs from cleaning in that it aims to stabilize and preserve existing surfaces rather than restore a “like new” appearance. If a coin has developed harmful deposits or active corrosion, professional conservation may be warranted. However, routine cleaning with commercial products almost always damages coins and should be avoided.

For handling error coins, always use cotton gloves to prevent oils and acids from your skin from transferring to the coin surfaces. Even the natural oils in human skin can accelerate toning and create permanent fingerprints on sensitive surfaces.

Specific Preservation Considerations for Different Error Types

Each error type in this collection presents unique preservation challenges:

CUD Errors (1984 Lincoln Cent)

The dramatic cud on this coin creates raised metal edges that can be prone to nicks and scratches. The MS65RD grade indicates exceptional preservation of the red coloration, which requires protection from environmental factors that could accelerate toning to brown.

Off-Metal Strikes (1994 Lincoln Cent)

Struck on unplated planchets, this coin’s exposed copper is particularly vulnerable to oxidation. The MS64 grade suggests careful previous handling, and maintaining this condition requires vigilant environmental control.

Struck-Through Errors (1970-D Jefferson Nickel)

The retained copper strike-through creates a raised element that could be damaged through improper handling. The MS62 grade indicates some contact marks, making preservation of the remaining original surfaces crucial.

Double Strikes (1973-D Kennedy Half Dollar)

The dramatic 85% off-center second strike on this coin creates multiple high points vulnerable to wear. The MS62 grade and the interesting detail of the flipped date make this coin particularly significant for preservation.

Brockage Errors (Lincoln Cent)

The full brockage creates a mirror image of one side on the other, with the original design appearing incuse and reversed. The MS62BN grade indicates brown coloration, and preserving the contrast between the mirrored and normal surfaces is essential.

Long-Term Preservation Strategy

For collectors building significant error coin collections, developing a comprehensive preservation strategy is essential:

1. Document current conditions with high-resolution photographs
2. Establish proper storage conditions with stable temperature and humidity
3. Use only archival-quality holders and materials
4. Limit handling and always use appropriate protective equipment
5. Consider professional grading for valuable pieces to provide long-term protection
6. Regularly inspect coins for signs of environmental damage or deterioration

The decision to submit these 28 coins for professional grading demonstrates understanding of the value of expert preservation. While most may not be “special” individually, slabbing provides protection that maintains their collective value and ensures they remain in collectible condition for future generations.

Conclusion: Preserving Numismatic Heritage

These exceptional error coins – from the dramatic cud on the 1984 Lincoln Cent to the fascinating double strike on the 1973-D Kennedy Half Dollar – represent important pieces of minting history. Their preservation requires understanding the specific vulnerabilities of each error type and implementing appropriate protective measures.

The numismatic community benefits when collectors prioritize preservation over short-term display or risky cleaning attempts. By following proper storage protocols, using appropriate holders, and understanding the risks of environmental damage, collectors can ensure these remarkable error coins survive in excellent condition for future generations to study and appreciate.

Remember that the value of error coins often lies not just in their rarity but in their preserved state. A coin graded MS65RD represents a significant premium over the same coin in lower grades, and this premium exists because someone took the time to preserve it properly. Your careful preservation today ensures these fascinating pieces of minting history remain available for tomorrow’s collectors and researchers.

Related Resources

You might also find these related articles helpful:

• What is the Real Value of an 1884 Morgan Dollar in Today’s Market? – Pinpointing the true value of an 1884 Morgan silver dollar requires looking past the book price and understanding curren…
• Grading New Error Coins: How Wear, Luster & Strike Quality Determine Value From $20 to $2,000 – Condition is everything. In the world of error coin collecting, a pristine strike can mean the difference between a mode…
• The Silver & Gold Content of Newp 1893 Indian Cent Explained – Historical Significance The 1893 Indian Head Cent stands as a testament to a pivotal era in American coinage. Minted dur…