Does Cleaning Coins Decrease Their Value?
Does Cleaning Coins Decrease Their Value?
Essential guide to coin preservation and why cleaning almost always reduces collectible value
The Golden Rule of Coin Collecting
When it comes to cleaning a coin, the general rule of thumb is simple: don't clean your coins. Cleaning coins is not only generally harmful to their value, but it can also irreparably damage their surfaces—rendering many pieces numismatically uncollectible.
Many people want to know if cleaning coins reduces their value, and the answer isn't as complicated as some may believe. This comprehensive guide addresses common questions about coin cleaning and explains why this practice causes coins to lose their value, often dramatically.
Critical Warning
Cleaning permanently damages coin surfaces by removing the outer layer of patina or toning, usually by scraping away a thin layer of metal. This creates countless tiny scratches that are visible under magnification and can drastically reduce a coin's numismatic premium and collectible appeal.
Collector's Guide Contents
Why cleaned coins lose their value
Several factors explain why cleaning coins causes them to lose value. In the most basic sense, most collectors simply don't want their coins cleaned. They generally desire originality—they want their coins to appear unadulterated and authentic to their historical period.
Damage Mechanisms from Cleaning
Cleaning a coin permanently damages its surfaces by removing the outer layer of patina or toning. This patina may appear "tarnished" or "dirty" to amateur eyes, but it represents the coin's natural aging process and historical authenticity.
The removal of this metal typically results in countless tiny scratches or hairlines across the coin's surface. In the "best" cases, these are only visible under 3X to 5X magnification. In worst situations, these striations are hideous and clearly visible to the unaided eye.
Collector Psychology
- Preference for original, unaltered surfaces
- Historical authenticity importance
- Natural aging process appreciation
- Suspicion of artificial enhancement
Market Impact
- Reduced buyer interest
- Lower numismatic premiums
- Eliminated eye appeal
- Decreased collectibility
Physical Damage
- Microscopic surface scratches
- Removed patina and toning
- Lost original mint luster
- Altered surface texture
Bullion Coin Effects
- Reduced numismatic premium above spot price
- Potential metal loss from abrasive cleaning
- Damaged collectible appeal
- Lower resale value even for modern coins
Numismatic Value Components
Remember that most of a coin's value stems from its numismatic value—a combination of rarity, grade, and eye appeal that usually comprises the largest share of overall value. Even modern gold and silver bullion coins typically trade at premiums above precious metal content due to their numismatic characteristics.
Impact on professional grading and "Details" grades
Professional grading services like NGC and PCGS play a crucial role in the modern coin market, and their treatment of cleaned coins has significant value implications for collectors and investors.
Professional Grading Service Response
When a cleaned coin is authenticated by leading third-party grading services such as NGC or PCGS, the coin receives a "Details" grade. This designation indicates the coin no longer has original surfaces and has been altered from its natural state.
Grading Impact Comparison
| Coin Condition | Grade Assignment | Market Reception | Value Impact |
|---|---|---|---|
| Original Surfaces | Numerical grade (MS-60 to MS-70) | Full collector acceptance | Maximum market value |
| Improperly Cleaned | "Details - Cleaned" designation | Limited collector interest | 20-50% value reduction |
| Harshly Cleaned | "No Grade" or "Genuine" | Minimal collector appeal | 50%+ value reduction |
| Professionally Conserved | Numerical grade possible | Accepted if successful | Value preservation possible |
Market Reality
Coins with "Details" grades have significantly lower values in the collecting marketplace. The designation serves as a permanent warning to potential buyers that the coin's surfaces have been compromised, making it less desirable than comparable examples with original surfaces.
Grading Service Standards
- NGC and PCGS authenticate all submissions
- Detailed surface analysis under magnification
- Consistent application of grading standards
- Protection for collector confidence
"Details" Grade Implications
- Permanent designation on holder
- Reduced resale value
- Limited collector demand
- Investment appeal compromise
Safe cleaning methods that preserve value
While the general rule is never to clean coins, there are extremely limited circumstances and methods that may not completely destroy a coin's value. These approaches focus on removing surface debris without altering the coin's patination or toning.
Non-Destructive Methods
The only ways to "clean" a coin without completely destroying its value involve non-abrasive methods that don't alter the patination or toning. These techniques remove surface contaminants without damaging the coin's underlying surface.
Water Rinse Method
- Use slow stream of tepid water
- No rubbing or scrubbing motions
- Pat (don't rub) dry with soft cloth
- Removes loose surface debris only
Acetone Treatment
- Use 100% pure acetone only
- Work in well-ventilated area
- Brief soaking for adhesive removal
- Rinse thoroughly with clean water
Realistic Expectations
Neither method will satisfy individuals trying to make chocolate-brown Lincoln wheat cents look bright and orange as if minted yesterday. There is simply no way to achieve such results on old, circulated coins without causing permanent damage that eliminates collectible value.
What These Methods Cannot Do
Safe cleaning methods cannot restore original luster, remove deep toning, or make old coins appear newly minted. Attempting to achieve such results will inevitably damage the coin's surfaces and destroy its numismatic value. Even if dramatic results were possible, the artificially enhanced appearance would be immediately recognizable to experienced collectors who avoid such altered pieces.
There is ongoing debate in numismatic circles about "properly" versus "improperly" cleaned coins, with some believing store-bought formulas and DIY methods represent acceptable approaches. However, no cleaning method for coins is promoted or endorsed by any major numismatic organization, emphasizing the inherent risks involved.
Should you clean coins before selling?
The decision to clean coins before selling them typically stems from fundamental misunderstandings about collector preferences and market dynamics. Understanding these factors helps explain why cleaning usually reduces rather than enhances resale value.
Common Misconceptions
- Belief that shiny coins are more valuable
- Assumption that cleaning enhances appeal
- Misunderstanding of collector preferences
- Confusion about market standards
Market Reality
- Collectors prefer original surfaces
- Authenticity trumps artificial enhancement
- Historical character adds value
- Natural aging reflects coin's journey
Antiques Parallel
- Similar principles apply across collectibles
- Original finishes preferred in most cases
- Restoration requires extreme expertise
- Amateur attempts usually destructive
Exceptional Cases
- Ancient coins requiring identification
- Removing harmful oxidation
- Professional conservation only
- Extreme caution always required
Classic Car Analogy
Interestingly, classic car restoration represents one collectibles area where cleaning and polishing maintains value. However, even then, harsh or abrasive cleaning agents are never used on collectible vehicles. The key difference is that automotive restoration involves proven techniques and professional expertise, unlike amateur coin cleaning attempts.
Internet Misinformation
Many online forums explaining how to clean coins pitch abrasives or caustic chemicals aimed at completely removing patination. While these methods may satisfy those who believe they're removing "100 years of dirt," they actually remove the coin's natural surface and irreparably damage its appearance, collectibility, and value.
One of the few numismatically acceptable times to clean coins before selling is with ancient coins that have been buried for millennia. Cleaning may be necessary for identification purposes, but even then, extreme caution and professional expertise are essential to avoid destroying archaeological and numismatic value.
Professional conservation and restoration services
When coins genuinely need help, professional conservation and restoration services offer the only viable alternative to amateur cleaning attempts. These services employ sophisticated techniques and equipment unavailable to individual collectors.
Professional Service Options
Major grading services offer restoration and conservation services that can evaluate coins and determine if professional work can improve appearance without damaging surfaces or overall value. These services represent the only way to avoid "Details" or "Improperly Cleaned" grade designations.
PCGS Restoration
- Professional evaluation and treatment
- Specialized equipment and techniques
- Preservation of original surfaces
- Grading service integration
NGC Conservation
- NCS (Numismatic Conservation Services)
- Scientific conservation methods
- Problem coin evaluation
- Certification coordination
Archaeological Approach
Professional conservation services employ techniques similar to archaeological artifact preservation—carefully removing harmful contaminants while preserving original details and surfaces. This approach aims to bring out original coin features rather than artificially "cleaning" them.
These services have achieved success with coins suffering from ugly toning issues, surface residues, or other numismatic problems that make pieces less market acceptable. However, no service guarantees results, and not all perceived "problems" can or should be addressed.
Service Capabilities
- Toning issue resolution
- Surface residue removal
- Environmental damage mitigation
- PVC damage treatment
Limitations
- No guaranteed outcomes
- Cannot fix all problems
- Expensive professional fees
- Time-consuming process
Proprietary Methods
- Trade secret techniques
- Specialized equipment access
- Years of research and development
- Scientific approach to conservation
Integration Benefits
- Seamless grading service workflow
- Avoided "Details" designations
- Professional documentation
- Market acceptance enhancement
Frequently asked questions about coin cleaning
The impact depends somewhat on individual collector preferences, as the adage "beauty is in the eye of the beholder" applies. However, for the vast majority of coin collectors, any coin with altered surfaces is worth significantly less than examples with original surfaces. Even collectors seeking "shiny-looking" coins typically prefer naturally preserved pieces over artificially cleaned ones.
There is no completely safe way to avoid reducing a coin's value through cleaning. The best advice involves using the least abrasive methods available—tepid water rinses and pure acetone for specific contaminants—while avoiding harsh chemicals entirely. However, even these methods carry risks and cannot achieve dramatic cosmetic improvements without causing damage.
Not necessarily, but coins appearing "dirty" with original toning are generally more valuable than cleaned examples. Authentic old coins exist that were well-preserved and never accumulated dirt. However, coins with natural toning or patina are more likely to be genuine and collectible, and won't receive "Details" designations from grading services.
Boiling coins is not recommended for any reason. Depending on a coin's metal composition, the boiling process may result in discoloration, surface damage, or other alterations that reduce collectible value. The extreme temperature can cause thermal stress and potentially damage the coin's molecular structure.
Professional conservation services like NGC's NCS and PCGS restoration use proprietary methods that remain trade secrets. These techniques focus on removing harmful contaminants while preserving original surfaces, similar to archaeological artifact conservation. The goal is revealing original details rather than "cleaning" in the traditional sense, though positive results are never guaranteed.
Conclusion
The evidence overwhelmingly supports the fundamental rule of coin collecting: don't clean your coins. Cleaning permanently damages coin surfaces, reduces numismatic value by 20-50% or more, and eliminates the originality that collectors prize most highly. Professional grading services reinforce this principle by assigning "Details" grades to cleaned coins, significantly reducing their market acceptance and value.
For collectors concerned about coin appearance, the safest approach involves extremely gentle methods like tepid water rinses for removing loose debris. However, even these techniques cannot achieve the dramatic cosmetic improvements that motivate most cleaning attempts without causing permanent damage.
When professional help is genuinely needed, conservation services from major grading companies offer the only viable alternative to amateur cleaning. These services employ sophisticated techniques unavailable to individual collectors, though success is never guaranteed and costs can be substantial.
Preservation Philosophy
Whether collecting historical coins, modern gold bullion, or silver pieces, the preservation philosophy remains consistent: original surfaces and natural aging represent authentic historical character that artificial enhancement cannot replicate. Collectors value this authenticity far more than artificial brightness achieved through cleaning.
For new collectors, embracing the natural appearance of coins—including toning, patina, and age-appropriate characteristics—opens doors to appreciating numismatic artistry and historical significance. The temptation to "improve" coins through cleaning almost invariably destroys the very qualities that make them valuable and collectible in the first place.