While it is obvious today that to authenticate a coin, you must know what the genuine coin should look like, at one time this was taken for granted. When I became an authenticator, I never saw it expressed anywhere! I am certain this primary “rule” of authentication was formalized in print and passed on during our authentication seminars starting in 1973 due to a very fortuitous event.
One day at the Certification Service, we almost returned a very worn 1915-S Pan Pac $50 (carried as a pocket piece) to a walk-in the customer as a cast counterfeit because it looked so crude under a microscope
