1893 Mexican Cap&rays 8 Reales, Fake Or Not?

Volvicch Reviewing the pictures and data as presented - I would accept the coin as being genuine. Diameter was not fully standardized between mints or even within the same mint because of multiple rolling mills. Mexico City had the best control of all but it was not perfect.

As to the SG test. A scale accurate to 1/100th gram can give you an accurate test to ONE decimal point all other factors being controlled. It takes practice but completely repeatable results can be achieved using a good 0.01 gram scale. I suspect the problem is the volume calculation - that is the most difficult part to master. The weight lost in water (grams) exactly equals the volume of the coin in cubic centimeters.

jgenn In 1893 Mexico City was making dies for all the branch mints and working dies were hubbed. Variations appear due to multiple hubbing and die damage once they were placed in service. Mint marks and assayer initials were added locally. Touch-up recutting is also well attested.

The planchet was edged in a multiple planchet edger and stuck in place for more than one revolution hence the multiple image on the edge.

@ Swamperbob Thanks for sharing your knowledge, I guess I will hang onto it.

@ xlrcable Yeah I noticed that as well. I managed to suspend the coin from a single loop of sewing thread, using a running knot so I don't think that would influence the result of the SG test at all.

I don't know what clean is, the mag should very slowly drag.
Do you mean it did not slip off fast?
I use your method at coin shows, but in my shop I suspend the magnets to see if a coin presents an opposing force. And I have a nice magnet slide. All useful, but not without false results for some other metals. But in those cases, the weights and density will prove to be wrong.