Is This Mexican 8 Reales Fake?

Swamperbob will definitely have something to say about this one, since the 1882 Zs are transitional types. To me it appears to be a counterfeit, since prior to 1882 Zacatecas used dies closely resembling Mexico City, but did not start using actual Mexico City ones until 1882. After that time you can also check for "dragon teeth" at the base of liberty cap around the middle ray. They are an anti-counterfeiting feature on Standardized dies and look like this:



Looking forward to Bob's response...

~Roman