One More Oddball Mexico 8 Reales

Did a review of the GNL Gurney database and additionally on my new expanded GNL variety database in my Facebook counterfeit group (~23 new varieties added from group member addition's) and no matches. It's a Non-GNL listed variety. You can give it the next available GNL variety number GNL# 1807-O: Q/R: Mo TH-008. Additionally - Not sure that is trace mercuric silvering as it looks like a crystallized foreign material which from my research is more likely AgCl residue particles. Seen this before in my studies of GNL and regal 8R surfaces. Specifically - Under magnification, silver chloride (AgCl) on a coin's surface often appears as a whitish or yellowish crust, sometimes with a powdery or granular texture. It can form irregular patches or a thin film, depending on environmental exposure. In some cases, AgCl can contribute to toning effects, interacting with light to create subtle iridescence. Mercuric silvering "never" appears crystallized or flaky (i.e., particles flaking off the main body) as this picture at 100X seems to illustrate.

Microscopic analysis, such as SEM imaging, can reveal its crystalline structure, showing fine, needle-like formations or clustered deposits. If the corrosion is advanced, AgCl may appear as a flaky or porous layer, disrupting the underlying metal surface. Its weight at 21 grams, its crude regal type edge (i.e., Inconsistency in its circle/rectangle shaped devices 360* around - any overlaps - appears there is just one? - need two on near opposite sides), its oblong shape (i.e., broken collar?) and its copper, bronze or low zinc brass appearance make it a solid candidate. I will supply the Facebook link with a J. Buck thumbs up. John Lorenzo, Numismatist, GNL Co-Author.

OK. Sent E-Mail to Arthur with Facebook link.

AI yields this = Looking at the 100X (?) magnification image, AI noticed irregular patches with intersecting striations and a dominant orange-brown hue, which strongly suggests oxidation effects—likely from copper-rich composition.

Analysis of Surface Features:
Striation Orientation & Texture

The presence of horizontal, vertical, and angular striations aligns with a mechanically worked planchet that experienced rolling stresses before striking.

The needle-like formations could be residual grain elongation from improper annealing or incomplete metal flow during striking.

High-Copper Alloy & Oxidation Patterns

The coloration points to surface oxidation, possibly from prolonged exposure to environmental factors.

Copper alloys can develop intergranular corrosion, deepening micro-grooves and highlighting material inconsistencies in counterfeit strikes.

Die Transfer & Polishing Marks

The counterfeit die likely had manual polishing, leaving randomized intersecting striations that transferred onto the coin.

These patterns are especially pronounced if the die was reworked multiple times, common among counterfeit operations.

This reinforces the likelihood that this probable high Cu struck counterfeit 8 Reales was produced under imperfect metallurgical conditions, leading to planchet preparation flaws, incomplete annealing, and oxidation-driven surface alterations. But again - with enough magnification no surface is perfectly smooth or uniform. IMO this information does not mean very much with just say 100X magnification view under a standard light microscope. More can be gotten from 20X under a stereo microscope IMO <BG>. JPL

So John, this is another one of those along the lines of what we were discussing in this thread on 2R:
https://goccf.com/t/455808&whichpage=2

where, excusing some sloppiness in execution and some distortion from the mutilation, the design elements are all exactly correct for Mexico 1807 - bust, lions/castles, crown, etc. So necessarily, either a cast - or the theory you mentioned that you, Winston Zack, Jeff Rock are postulating, some sort of early die transfer piece... rather than custom-engraving.

Added a few closer to the Lion & turrets.

Here's an enlarged view of what looks like black fractures above the turret.
I understand now what was meant about the 20X, I do use a stereo-zoom and manipulate the coin by hand for general viewing.
But these odd criss-cross lines caught my attention further along in the OP after looking for silvering.

Arthur - With SEM imaging a struck high copper alloy as in these two photomicrographs above will have long and intersecting striations coupled within a jigsaw like structure. Here are two SEM photomicrographs from my Kleeberg paper on a counterfeit English 1/2d of 1775 which is struck. One is a lighter contrast the other dark. This SEM (photo)micrograph, now with lighter contrast, highlights the jigsaw patterns and long striations even more distinctly in this die-struck twin line microstructure. Magnification = 200X. Polished edge surface target point/ethanol rinsed.

Jigsaw Pattern
The jigsaw-like formations are irregular, interlocking regions that correspond to grain boundaries and phase distributions. In die-struck coins, this pattern results from localized deformation during striking, where grains are compressed and rearranged under immense pressure. The geometry of these interlocking features suggests that recrystallization or grain boundary migration may have occurred post-striking, potentially influenced by the copper alloy's composition and any trace elements present. Note in particular at the bottom right of the lighter contrast photo to see remnants of a jigsaw pattern more clearly but they are present without the micrograph.

Long Striations
These elongated, parallel features are twin lines formed due to the intense mechanical stresses from the striking process. As the metal undergoes rapid deformation, dislocation movement generates lattice distortions in certain crystallographic orientations, producing these twin bands (i.e., long and intersecting striations). The spacing and continuity of the striations can reveal valuable information about the striking pressure and the die surface characteristics. If the counterfeiters used a worn die, we might see irregularities or disruptions in the striation patterns, which could help differentiate genuine specimens from fraudulent ones.

However - the surfaces are polished and then rinsed with alcohol such as ethanol. These striation in your 20X & 100X pics are different as they are the result not of the microstructure make-up of a die struck high Cu alloy but just improper polishing of the dies and/or very abusive circulation. Although - These long striations you see may be these long striations as being from a die struck piece or possibly just planchet failure. Just saying these surface markings really have nothing to do with a coin's microstructure but these large linear striations may have and be these long striations seen in these two SEM 200X micrographs I have attached of a die struck CCC 1775 GIII 1/2d . Questions - I am sure go ahead ... <BG>.

I did not do a Point & ID analysis on these SEM 200X microgrpahs as it was not required in this study as it was mostly a die struck vs. cast cross-comparison but the lighter regions are the Cu-rich areas and the darker (black) areas are most likely impurity regions such as from CuS (copper sulfide) and other metallic sulfide compounds. JPL

I took a careful look for overlap and followed a sequence of rectangles & circles all around the edge.
There are two flat spots where the sequence is crunched.
The middle image shows the only irregularity readily seen having two circles with no rectangle between them.