Coin Talk

Numismatic Malpractice
July 15, 2011 By Michael Bugeja 4 Comments

I purchase coins on the Internet portal Proxibid, monitoring all numismatic auction houses for my personal site, Proxiblog. I send raw coins for my set registry to PCGS. Ones returned to me as altered have distinct characteristics-the topic of this post.

Whizzing constitutes numismatic malpractice. Coin doctors use of a high-speed drill with a brush-like implement, which used to be easy to detect because the process often damaged the cartwheel effect on Morgan dollars and overshot devices on small coins like Mercury dimes. However, in recent years, those tools have become more sophisticated with dentist-drill-like speeds and micro-fiber abrasives. Combined with other methods, such as heating the metal to erase the hairlines or dipping and toning methods to unify the sheen, these doctored coins are becoming more difficult to identify.