8 Reales 1825 Potosã­ Fake/Counterfeit

No two 180º overlaps. Just one
I will add photographs later
I rely more in physics than in human sense ;)

Here we are

Interesting edge shot... No, there isn't an obvious overlap, though with everything a bit mushy from wear, would be hard to discern a subtle overlap (where the alignment is almost exact).

One feature from that shot that reassures me about the piece are those striations (visible all the way to the left... on the left-side photo in the composite pic). What causes that exactly, don't know, but you see it on good pieces.

The lack of gold and platinum is odd though, assuming it's not test error. Uneducated thought - 1825 is obviously as late a colonial as you can get, and getting toward that period where they could/would remove those traces and where platinum turned into a precious metal. Is there no chance that this could be a very early instance of that? I know you guys have mentioned 1850 or so at a date for that; Potosi was right next to the mine, of course... maybe they had some modern scientific/engineering input there? John, do you guys have any test results for late Potosi (1824, 1825) in your research? If so, any differences noted with, say 1780ish Mexico?

The one thing I'll note... 1825 JL is a somewhat plentiful date. That's kind of curious for being the last colonial issue, especially comparing them to the Lima/Cuzco mintages of these late years (unless the loyalists in Potosi wanted to go out with a bang and make a statement of support?).

John, stupid aside - and I apologize as I've never gotten fully through those papers (L. Beck, etc.) you've posted discussing surface enrichment, etc., which may address this. I've kind of wondered about surface metallurgy of a coin... it is feasible that metals which are "softer" on the Möhs scale (umlaut, I think?) might actually wear away through circulation a bit more quickly than "harder" metals at the molecular level, leaving behind artificially higher ratios of those harder metals?

Thanks for that info... the frozen date explains why so many. Was the rationale for that the simplest reason you'd expect - they couldn't prepare new dies - or was it something else?

I did assume it was the same assayer(s) JL as the 1827 Bolivar issues... similar to Mexico City, yes? (and maybe Guanajuato at least in part?). I'm not real knowledgeable on the EXACT timeline of who controlled what in each region/mint, so I just assumed it was a "Hey, we'll put whoever you want on the coins - just let us keep our jobs and don't shoot us" kind of thing.

Just E-Mailed Bob Gurney so he should be around shortly. Realeswatcher - sure - on shipwreck pieces copper as you figure would leach out of the coin given enough time and seawater corrosion - I have analyzed pieces from the Calzador near or at 99% Ag!

Still can't explain the lack of Au & Pt. To me only two possibilities a testing error or modern. From her analysis (Spain) that seems to be a pretty good instrument. On 20th C silver pieces we may detect Pt and Au around 0.001% levels.

Sure its a piece maybe that should be sent to Bob in hand ... ? Takes forever to get pieces from Spain to NJ for example ... normally a MONTH ... even registered.

JPL

Unfortunately I am not sending my coin to the US.
I am pretty sure, of course never 100 %, that this coin is not good because various details, not just one.

Sure Moneditis its not worth it on this piece. BTW I developed my method that I used in the MNA Chihuahua Cast/Restrike 8R War of Independence Study Paper ORIGINALLY from the work of P.T. Craddock of the British Museum whom I am sure you heard of before ... this trace Pt/Au is in his Forgery Antiques book under the coin section. I worked via E-Mail with Craddock on some ideas with copper awhile back with shipwrecks and copper ingots particularly the high Bi found in George II coppers and low Bi and high sulfur in George III coppers as signature trace elments.
In our book forthcoming from the ANS in early 2015 in the XRF analysis we identify about (14) different alloys including the silver plated Sheffield process in contemporary counterfeit 8 Reales for the Portraits. Over 1,000 coins are plated into two CDs. Over 500 Class 1 pieces which circulated with the regal (legitmate) issues are plated and described. This along with identifying the modern Chinese fakes, etc. - if you own a Portrait 8 R - you will want this book - yes self promotion - but review the Table of Contents at the next coin show after its released and make your own judgments <VVBG>. Some great XRF and SEM/EDS material in a whole separate chapter.

John Lorenzo
United States