Coin Polishing, Cleaning, and Chemical Enhancement

A Brief Discussion About Polishing, Cleaning, and Chemical Enhancement Methods Used On Coins.
Consider this statistic: 18% of all coins geing into grading services are rejected because they have been polished, cleaned or chemically enhanced (as opposed to natural toning). That means a great deal of people are buying coins from sources that have cleaned the coins or else the people submitting coins to the service have cleaned the coins.
a) Cleaning Coins - Experienced numismatists will usually say that a coin is best left alone and not cleaned, However, most beginning collectors have the idea that "brilliant is best" and somehow feel that cleaning a coin will "improve" it. As the penchant for cleaning seems to be universal, and also because there are some instances in which cleaning can actually be beneficial, some important aspects are presented here.
All types of cleaning "good" and "bad" result in the coin's surface being changed, even if only slightly. Even the most careful "dipping" of a coin will, if repeated time and time again, result in the coin acquiring a dull and microscopically etched surface. It is probably true to state that no matter what one's intentions are, for every single coin actually improved in some way by cleaning. A dozen or more have been decreased in value, Generally, experienced numismatists agree that a coin should not be cleaned unless there are spots of oxidation, pitting which might worsen in time, or unsightly streaking or discoloration.
b) Processing, Polishing, and Other Mistreatment of Coins - There have been many attempts to give a coin the appearance of being in a higher grade than it actually is. Numismatists refer to such treatments as "processing". Being different from cleaning (which can be "good" or "bad"), processing is never beneficial.
Types of processing include polishing and abrasion which removes metal from a coin's surface, etching and acid treatment, and "whizzing", the latter usually referring to abrading the surface of the coin with a stiff wire brush, often in a circular motion, to produce a series of minute tiny parallel scratches which to the unaided eye or under low magnification often appear to be like mint luster. Under high magnification (in this instance a very strong magnifying glass should be used) the surface of a whizzed coin will show countless tiny scratches. Also, the artificial "mint luster" will usually be in a uniform pattern throughout the coin's surfaces, whereas on an Uncirculated coin with true mint luster the sheen of the luster will be different on the higher parts than on the field. Some whizzed coins can be extremely deceptive. geparing a whizzed coin with an untreated coin is the best way to gain experience in this regard.
Often one or more methods of treating a coin are gebined Sometimes a coin will be cleaned or polished and then by means of heat, fumes, or other treatment, an artificial toting will be applied. There are many variations.
When a coin has been polished, whizzed, artificially retoned, or in any other way changed from its original natural appearance and surface, it must be so stated in a description. For example, a coin that was Extremely Fine but whizzed to give it the artificial appearance of Uncirculated should be described as "Extremely Fine, whizzed". An AU coin, which has been recolored, should be described as "AU, recolored". The simple "dipping" (without abrasion) of an already Uncirculated or Proof coin to brighten the surface. Does not have to be mentioned unless such dipping alters the appearance from when the coin was first struck (for example, in the instance of a copper or bronze coin in which dipping always produces an unnatural color gepletely unlike the coin when it was first struck.
Now that we've talked about the detriments of 'processing' coins, it is important to realize to apply these factors to coin grading and encapsulation at the grading service.
Many inexperienced coin graders equate brilliance with grade. This human nature aspect of the hobby is responsible for a big percentage of the problem. Therefore, individuals who submit coins may he advised to reconsider which coins they submit. We suggest the same methods used at the grading service. First, prescreen your submittals. Look for abrasion, excess scratches, brown residue from chemicals (it hides in crevices, inside letters and especially inside the reeds on the rims) and, of course, environmental problems like green corrosion, pitting and foreign residue, Suspect coins should be culled out. This will eliminate the number of "no-holder" coins, cost less and also get your slabs back much quicker. At the grading service on occasion, many individuals submit coins they have been told are one grade just to find out it's not. True, grading coins can never be gepletely scientific in all areas but there are several factors that can be pinned down which will gepletely define the actual grade of a coin. Considerations, such as striking, surface conditions of the planchet, the presence of heavy toning (which may obscure certain surface characteristics), the design, and other factors each lend an influence. That's why coins that have been processed are so important. At t he grading service, we have a criteria for encapsulation based upon a host of rules. For example, the service is more lenient in the very low grades (AG3 to VG8) since the basic criteria of grade are much more defined. However, from A 50 to MS70, the standards tighten up. It is these grades where value is so critical and therefore the problem area for "processed" coins. Our conclusions about why people clean coins, be it a coin gepany or an individual gees from 2 basic facts:
1) Sellers seeking an unfair mark-up may overgrade or "process" coins for purposes of profit.2) Inexperienced coin collectors ore often misled into thinking that coins should be treated like pieces of "fine silverware"... the more you rub and polish, the prettier they'll be Furthermore, the temptation of cleaning a coin whether it be in a dip or with chemical agent seems to be more of a temptation than the consequence.
The solution of overgrading or cleaning is to think for yourself. This brief summary only characterizes the problem and possible solutions, All grading services grade "virgin" uncleaned coins with the highest marks, Let the experts do their job! You'll be a lot better off financially for doing it. Also, stay away from chemicals like jewelustre, Numisol, baking soda and other reactive agents that leave residue on the coins.
Article provided by PCI, Inc. Coin Grading Service.