Articles

What are "Wheel Marks"?

Submitted by JonSullivan on Tue, 02/03/2015 - 07:24

Here is an excellent article on the subject, put out by NGC. It will describe in detail what they are, and how to detect them. http://www.ngccoin.com/news/viewarticle.aspx?IDArticle=4412&Wheel-Marks

Comprehensive Error-Variety Checklist

Submitted by JonSullivan on Sat, 05/30/2015 - 13:52

Comprehensive Error-Variety Checklist

 

Compiled by Mike Diamond

 

 

This checklist is my attempt to compile a comprehensive listing of all known variety and error types, subtypes, and associated effects.

Off-Metals

Submitted by JonSullivan on Fri, 05/29/2015 - 13:33

Off-Metals 

by Jon P. Sullivan

Double-Strikes

Submitted by JonSullivan on Fri, 05/29/2015 - 13:19

                                                                                                                                                                                                     Double-Strikes

                                                                                                                                                                                                   by Jon P. Sullivan