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 Replies: 12 / Views: 1,578 |
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Pillar of the Community
United States
1757 Posts |
1811 Zacatecas Moneda KM-190 LVO XRF Analysis Overview - Germany Example - As part of an investigation in the 1811-1814 Chihuahua Cast XRF analyses for a future MNA paper the collector from Germany sent me an LVO Mexican piece as part of the coin package from a noted sale. See here: http://stacksbowers.com/Auctions/Au...LotID=399485Specimen weighs 21.4 grams, 37.9 mm with FILE MARKS on the edge. Again - I am not an expert on these pieces however I do know that all LVO pieces have smooth edges and not a regal type (i.e., square & circle) and are generally low weight against 26.5g. XRF Analysis of (6) spot analyses gave this typical assay: Ag(93.7%), Sn (ND), Fe (0.07%), Co(0.19%), Ni (0.03%), Cu(5.14%), Pt(0.21%), Au(0.20%), Hg(0.12%), Pb(0.22%), Bi(0.07%). From the above - The specimen showed good silver and a good platinum/gold ratio indicating it was of the period or regal silver was used in its manufacturer. Iron is normally considered an outside contaminant and could also come from poor manufacturing methods which could introduce high Fe. Some LVO's I see show this type of discoloration or poor silvering appearance - again - new territory in my opinion. The red or discolored areas? XRF did pick up anything unusual at the surface and the elevated silver (93.7% against 90%) was due to the L. Beck silver surface enrichment effect which basically indicates silver tends to the surface with time showing slightly elevated readings as this example with time. I have confirmed this with over 100 regal 8R's. The end result in my mind the discoloration which analyzed as regal silver, its low weight and the file marks indicated to Stacks this as a contemporary. LVO's seem to come low weight and with smooth edges. So some file marks should not condemn this example as a CC? Again more to follow with time. I consider this a real piece - at this time. John Lorenzo United States Edited by colonialjohn
03/10/2013 3:09 pm
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Pillar of the Community
France
1591 Posts |
I'll weight mine and tell you.
That's the smooth edge I showed you in the other topic :)
That one looks particularly crude compared to the other ones I've seen !
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Pillar of the Community
 United States
1757 Posts |
They all seem to come with smooth edges. I could not reproduce that high Fe so it seems it was a singular point of probable outside contamination that can be brought in from the coin making equipment. I did (12) further XRF spot analyses and all were low Fe (<1%). In the November Stacks Sale with other LVO's they tend to indicate that trait of smooth edges and no circles/squares. Yes - I remember your pic of the edge of your LVO. This could be another paper - will keep examing these pieces as I do have one coming in soon from a dealer. The Chihuahua casts are first & primary to the MNA.
John Lorenzo
United States
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Valued Member
Germany
194 Posts |
I was taking the host coin to be a contemporary counterfeit, just as Ponterio described it, for the simple reason that the quality of its strike is very much below the average Zacatecas LVO issue.
Another observation that made me wonder was that the die, especially of the shield and pillars side, was so much wider than the planchet.
I completely forgot to wiegh the coin before sending it to be tested, but 21.4g would be a very low weight. The Zacatecas LVO coin in my collection actually shows a weight of 29 grams!
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Pillar of the Community
United States
1757 Posts |
New territory for me but everyone I have seen come irregualrly struck? Whatever ... just gathering data at this point ... all your Chihuahua's BTW are real in my opinion ... good silver/ good Pt/Au ratios ... will post again later ...
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Pillar of the Community
United States
5362 Posts |
If the weight is low and the edge is not smooth as it should be - it could be a clipped coin. That would be a simple solution. An original cut down. But I tend to agree that the die work is VERY crude even for Zacatecas in the LVO era. Ponterio thinks it is a counterfeit. So how would you get a regal silver counterfeit that is 79% of standard weight? This could be an example of the process described in the M. Charles de Gimbernat report of May 19, 1796. Take and original 8R roll it down thinner to obliterate the original features. Then cut the perimeter off to leave a blank of the correct diameter only thinner. Then restrike it with false dies and place the coin back in circulation. For the example Gimbernat studied in 1796 the coin weighed 80% of correct (84 grains removed from 414) and this LVO example is 79% of correct. Sounds like you could have the FIRST known example of that technology to have survived. Super find if that is what it is. A technologically unigue coin. This could mean I have an edit to make if our book goes to second edition.  |
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Pillar of the Community
United States
1757 Posts |
The edges are filed but are very old - seems like something you would do to obtain free silver or that was done at the Mint to file down to a correct weight - but not with this overall weight. I will say one thing Bob - these War of Independence Issues seem to have there own rules - EACH SERIES. All other contemporary coinages I have collected/analyzed seem SIMPLE & PREDICATABLE. I am awaiting the Nichols group of (3) Chihuahua's then I will send you a draft - COMPLEX - so far - I think the non regal edge pieces are of the period but contemporary - be patient - the results are REMARKABLE <BG>.
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Valued Member
Germany
194 Posts |
A little takeaway from the last Ponterio auction, an armored bust Zacatecas type with an ENSAIE counterstamp. http://stacksbowers.com/auctions/Au...LotID=423017At this coin, the edge was seriously trimmed, down to a weight of 25.5g. The smaller diameter can be noted (not in the auction picture of course :-), also the coin is not evenly round any more... |
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Pillar of the Community
United States
1757 Posts |
I did some checking and as I mentioned I did some further XRF spot analysis on these brownish specs and brown discoloration but still basically came up with the same 90%Ag/10%Cu mix. See here: http://www.error-ref.com/improper-annealing.htmlAlthough this is an extreme example of copper coming to the surface due to improper annealing this could be the cause of this discoloration on this flan. I don't think its improper alloy mix as I did not see any CHANGE in constituents going from one XRF spot to another for these brownish specs or discolored areas. I feel these are copper spots or copper not properly mixed in with the Ag in this planchet. Notice the explanation of copper and nickel migrating to the surface if proper annealing is not performed - well in this LVO coin just the copper metal. This I believe "may be" a MILD situation of this phenomenon. Still not sure of the filing on this low weight flan but this may be a form of clipping or obtaining silver from this piece by a later third party outside of the mint operation? Filing of edges is also done on cast coins of copper to remove the burrs after casting - but again irrelevant here ... still see no reason to call it an unconditional counterfeit? John Lorenzo United States Edited by colonialjohn
03/10/2013 8:52 pm
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Pillar of the Community
United States
1962 Posts |
Quote:
Another observation that made me wonder was that the die, especially of the shield and pillars side, was so much wider than the planchet.
I completely forgot to wiegh the coin before sending it to be tested, but 21.4g would be a very low weight... Quote:
If the weight is low and the edge is not smooth as it should be - it could be a clipped coin. That would be a simple solution. An original cut down. These are NOT my field... but to me, that makes sense. As DosMundos said, there is a VAST amount of perimeter detail missing from the planchet as it currently is... ABSOLUTELY enough planchet space to get from 21.4g to the 25g range, I would think. Look at some other examples of LVO pieces on Ponterio, Heritage, etc. Also, is this really that crude for an LVO piece? These were generally a mess with many different variants, yes? Looking at the countermark, this piece looks to have nearly exact medal alignment... SO, even if it was off-center as made, it looks like the bulk of the metal was shaved off from the left edge of the mtn side/right edge of the shield side. John, what's the diameter of this piece? |
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Pillar of the Community
United States
1962 Posts |
Picked a fairly crude-designed LVO from auction archives and scaled the pics (the shield, mountain on each should just about match in size... assuming those features were about the same to begin with)... look at the difference in diameter. Just added another (same-scaled) well-done piece with an even more drastic size difference: I will say, though, that I don't see anything quickly viewing a few dozen pieces that matches the styling or the crudeness of the piece in question...  Edited by realeswatcher
03/13/2013 02:44 am
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Pillar of the Community
United States
1757 Posts |
All LVO's in the ANS Museum have Plain Edges. Just viewed them ... I am only conerned with Chihuahua's at this point - will re-examine the LVO's next ... the weight range of the LVO's are in/around 26.5 grams ... for now these are like West Indies pieces and Pridmore (reference book), Gordon (auction) and H.Wood (reference paper) ... plate match, is the weight OK and within tolerance? and keep your fingers crossed ... <BG>. It usually works out ... I will set-up a Mexican E-Mail group after you E-Mail (first time around) for this Chihuahua 8R Cast draft paper. Will feed your comments/suggestions prior to MNA submittal.
Edited by colonialjohn
03/13/2013 09:55 am
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Pillar of the Community
United States
5362 Posts |
A picture is worth a 1000 words. The coin appears to be a cut down example. That part is clear.
I still think the appearance is too crude to be real.
But XRF also does not lie so it is Regal silver.
Needs more study - especially the issue of how LVO issues were created prior to being struck.
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Replies: 12 / Views: 1,578 |
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Posted 03/10/2013 3:14 pm
