Error Coin Education (link)

AskRaq

Error Coin Education - Site Link

This was pretty interesting and informative, it also has photo examples.

I still didn't find out what a "Die Adjustment" is though... but NGC states that they designate them(?)

Rob85635

Cool link, thanks for the info

errormaven

Try buying a standard reference like The Error Coin Encyclopedia by Margolis and Weinberg or The Official Price Guide to Mint Errors by Alan Herbert.

By the way, the term "die trial" or "die adjustment strike" refers to a coin struck under low pressure. While some may be escapees from test runs, these errors also occur as the result of spontaneous equipment malfunction. There is no way to tell the difference in a simple, centered, low-pressure strike.

AskRaq

errormaven- thanks for your input, much appreciated!! I'll take a look for the 'encyclopedia' as I am assuming it would be the most comprehensive.

commoncents05

I second errormaven's recommendation of The Official Price Guide to Mint Errors by Alan Herbert. Even if you're not into errors, this book goes into great detail about the minting process.

-Paul