When is an error coin not an error?

Coin World contributing writer Mike Diamond addressed the concepts of “assisted error” and “intentional error” in his May 12, 2014, “Collectors’ Clearinghouse” column, where he defines the two categories of coins. In short, intentional and assisted errors are given “help” by mint employees. These employees are the spiritual descendants of the 19th century U.S. Mint employees who unofficially produced 1804 dollars, patterns and other rarities for sale to favored collectors and dealers. Such practices continued well into the 20th century, as a lot in a recent auction suggests.

Heritage Auctions’ April 23 to 27 Central States Numismatic Society sale offered a small number of visually appealing, desirable errors. Among them was lot 5200, a mated pair of 1973-S Washington quarter dollars. The Glossary of the Combined Organizations of Numismatic Errors of America defines “mated pair” thusly: “These coins were struck together in the coining chamber. They fit together perfectly.”

Most error collectors would love to own the pair of quarter dollars in the Heritage auction. They are visually striking and would be the centerpiece of anyone’s error collection. However, a thin cloud shades this pair of coins — a shroud no commercial dip can remove. Look at the date and Mint mark. The two coins are Proofs, bearing the S Mint mark of the San Francisco Assay Office, and they are all wrong for this kind of error.

We look at what makes this piece somewhat questionable next week.