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Coin Clinic: How Does Restoration Improve Coins?

What can a professional coin restoration service do to improve my coins that I can’t do by cleaning them myself?

Restoration services don’t “clean” coins; they restore them. Such services can remove artificially and deliberately applied contaminants, these contaminants having been caused by improper care or storage. This includes such contaminants as polyvinyl chloride, spots, and fingerprints. Restoration does not include removing scratches, dings and other related issues.

Will a properly restored coin be worth as much as a coin of the same grade that never required some form of improvement?

Third-party authentication and grading services are good about identifying coins that have been enhanced improperly or have been properly restored. Either will be identified in the information accompanying an encapsulated coin. Both will likely result in a coin of lesser value than a coin that never needed such servicing. The difference is that the professionally restored coin is typically more acceptable to collectors.

Gold coins don’t tarnish. How can I tell if my uncirculated gold coin has its original mint luster?

U.S. circulation-strike gold coins are composed of 90 percent gold, 10 percent copper. The mix results in a coin with a “warm,” orange peel-like glow to the surface when first struck. Uncirculated coins that have been cleaned will retain this orange color within some of the lettering devices. This color should be equally distributed across all surfaces if the coin is truly uncirculated and has never been cleaned.

There are some tiny dark spots on the surface of my $20 double eagle. What is this, and is it a problem?

Since circulation-strike gold coins are composed of a mixture of gold and copper, it is the copper that occasionally reaches the surface in an amount sufficient to result in spotting from environmental exposure over time. Some collectors avoid purchasing such coins; however, others understand the presence of such spotting indicates that the coin has retained its original mint luster – in other words, no one has cleaned the coin.

Is it possible for spotting to appear on gold American Eagle and American Buffalo gold coins?

There is sufficient copper blended with the gold in GAE coins that, in time, spotting may appear on the surfaces. American Buffalo gold coins are issued of purer gold and, for that reason, are less likely to develop spotting.