Soiled or stained stamps are sometimes cleaned with chemicals to improve the appearance of the stamp. Sometimes a cancellation is removed by cleaning, making a used stamp appear unused. Unless it is done to preserve the stamp, both practices are unethical, and are easily detected by experienced collectors. Cleaning usually lowers the value of the stamp.
Term applied to a coin whose original surface has been removed. The results may be slight or severe, depending on the cleaning method used.
a term applied to a coin whose original surface has been altered or removed
a coin that has dirt or toning removed with a cleaning agent. Cleaning ranges from light to severe, depending on what is used to clean the coin. Cleaning may disqualify a coin from being certified. TIP: leave cleaning to the professionals, as cleaning generally lowers the collector value of a coin.
When a coin has been cleaned with baking soda or other mild abrasives, it may take on a slightly washed out look. Most dealers can tell that the coin has been cleaned. For all practical purposes, however, it is impossible to tell if most silver or gold coins have been judiciously and expertly cleaned just once or twice in Jewel-Lustre(c) or soap and water, or any other basically non-abrasive solution. If the lustre or color of the coin appears even the slightest bit unnatural as a result of past cleaning, the coin is usually described as "cleaned" when catalogued for sale.
