A Question of color on a Buffalo Nickel

1Bufffan

On a golden toned Buffalo Nickel is it also natural to have the color purple? or is this an indication of left over cleaning agent. just trying to understand if this is natural or artificial toning. Thanks for helping me to understand.

pursuitofliberty

Almost impossible to give you a reasonable answer without images, but a true purple would be suspect.

Mr_Spud

Purple can occur naturally, but AT often produces purple. For nickels, if you AT them using the easiest techniques the following progression occurs (from my old educational AT experiments I did 20 years ago to teach people how to detect AT). This is a collage of the same coin taken during the AT process, you can stop the process at whatever color you want, but it’s hard to avoid that suspicious purple that often isn’t present on naturally toned coins

The sad part is that it automatically makes naturally toned coins questionable if that purple is present. Heres a bunch of AT coins I made during those experiments 20 years ago that have at least some of that unnatural looking purple