PCGS The Standart for the Rare Coin Industry

On the other hand, there are many coins in numismatic circulation which are artificially toned, and unattractively so. Grayish-purple coins toned by using Clorox are often seen, as are brownish-gray coins toned by procedures not known to me.

My general advice is this: if a coin appears to be attractively toned and is pleasing to you, then it is probably worth buying, but if the toning appears to be artificial (an intuitive situation, one not particularly well defined) or is unattractive, then stay away from it or buy it at a lower price. Consulting with an established professional can be of help in this regard, but be aware that even the most expert of experts can differ in their opinions, as was evidenced by two of the Liberty Seated dollars in the Norweb Collection.

Coins which have been polished, whizzed (treated with a wire brush to produce artificial mint lustre), or which have otherwise been subject to processes involving brushing, etching, acid treatment, and the like should be described as such when sold, and when purchased should be acquired at a reduction from the regular price level. I recommend that you don't buy such coins at all. Your best protection against these practices is to buy from an established dealer who guarantees his merchandise, or to buy slabbed coins (only rarely does a whizzed, burnished, altered, or processed coin make its way into a slab).

Storage, Display, and Handling

As the owner of a coin you are charged with keeping it safe for future generations. The only reason that we can enjoy beautiful Proof and Uncirculated coins today is that earlier generations of numismatists took care to handle them properly. Of course, many numismatists abused the privilege, as attested by the numerous cleaned and unattractive pieces in existence now.

When examining a coin you should hold it by the edges and over a soft surface such as a piece of cloth. Avoid directly breathing on a coin, for breath contains small amounts of moisture which will later develop into tiny flyspecks or spots, particularly on copper and nickel alloy coins. Never allow your fingers to come in contact with a coin's surface, or a fingerprint will gradually appear in the form of discoloration.