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Were The Colombia Royalist Provisional Coinage 8 Reales Of 1813 From The Popayan Mint Silvered?

 
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Author Previous TopicReplies: 6 / Views: 195Next Topic  
Pillar of the Community
United States
1553 Posts
 Posted 05/09/2022  6:33 pm Show Profile   Bookmark this topic Add colonialjohn to your friends list Get a Link to this Message
Recently picked up this very rare COLOMBIA; Royalist Provisional Coinage; 8 Reales, 1813. Popayan Mint specimen from the recent Sedwick Auction. See below:




From my experience mercuric silvered issues on a copper host the same process BTW as used with the Honduran Real Provisionals which were mercuric silvered and as Stickney so aptly puts it - fooled no one when issued based on their weights. It seems not to happen on all examples here with these Columbian 8Rs but since its been roughly determined recently this silvering process in most cases has an average thickness of ~ 8mm only from other numismatic investigators published in Academia. I am not here to question why NGC grades Honduran Provisionals with full or near full silvering get NGC graded as VF20/25/30's instead of AU 50/53/55s since the slightest frictional or circulation wear will unquestionably REMOVE this silvering layer - my inquiry if you look at this example is the white appearance of this Sedwick example - particularly on the reverse. Unfortunately from past experience a desktop XRF is required which has the ability to analyze in a vacuum (i.e., light element) and have Instrument Detection Limits (IDLs) near or more sensitive than 0.01%. We can also view this Stacks example which appears to contain a large amount of surface silvering:

https://auctions.stacksbowers.com/l...popayan-mint

This is just an alert if other South American collectors agree or disagree with this suggestion. Unfortunately XRF analysis can not analyze a coin within a TPG holder as the plasticizers interfere with the metallurgical results. Sometimes when analyzing mercuric silvering with contemporary circulating counterfeits in my past research projects as with the Forgotten & GNL books surface mercuric silver results as low as 2% or so can appear invisible to the eye and when trace if present on a coin's surface the silvering is usually located WITHIN the motifs of the coin (i.e., lettering or date). Perhaps on these other examples which appear just as copper multi-spot analyses may prove otherwise. Its not that far fetched as an issue with this denomination to be silvered when issued. Or possibly not? John Lorenzo (Numismatist) United States.
Edited by colonialjohn
05/09/2022 6:39 pm
Bedrock of the Community
Australia
19560 Posts
 Posted 05/10/2022  12:18 am  Show Profile   Bookmark this reply Add sel_69l to your friends list Get a Link to this Reply
Rubbed mercury on copper and bronze coins is not viable in the long term. The copper atoms in the coin will exchange places with the mercury atoms in the rubbed on layer over time. The result is that the fresh silver appearance will fade over the long term.

A molten silver wash would provide a more long lasting silvery appearance for a much longer period. This what the Romans did with their very base metal antoninianii in the late 2nd century.

Coin pictured suggests to me that it most probably had a mercury rub.
XRF analysis in the fields and between the letters should confirm.

Coins have to be broken out of holder to allow XRF analysis to be done, and accurate weight measurement taken. This is one of the reasons why I have never been enthusiastic about slabbed coins
Edited by sel_69l
05/10/2022 12:30 am
Pillar of the Community
United States
1553 Posts
 Posted 05/10/2022  08:47 am  Show Profile   Bookmark this reply Add colonialjohn to your friends list Get a Link to this Reply
Here is a good paper reflecting your thoughts on a research project done to try to simulate ancient silvering - attached below. There are dozens of articles in ancient & modern (i.e., post 1500) periods explaining mercuric silvering. Normally at the end the planchets are annealed to drive off the mercury due to its low boiling point but almost always trace mercury (i.e., <5%) is usually left behind and detected as a stable mercuric silvered compound and non-hazardous in this inert state. Unfortunately to send this one out it would cost around $400. I know someone with a cheap XRF gun for FREE but for what purpose? I already know they are silvered - I know the NGC label is WRONG where it states AU - cleaned. Lighter elements based on atomic weights usually below Magnesium (from memory) need a vacuum chamber for accurate quantitative values but an XRF gun nevertheless would indicate silver IMO IF detected at values greater than 1%. Obviously I might do the later - see my other paper in the Newman Portal on a 1821 Zacatecas 8R using a $400 analysis and showing it was not cleaned but metallurgically made with non-homogenous surfaces due to impurities in the alloy made during the critical time of Mexican independence. They did not publish it in the Mexican Numismatic Association journal since they needed a bigger sample population. I have to agree but at $400/coin - LOL.

See this ancient paper - one of my favorites for ancient silvering of coins which follows until silver plating and eventually Sheffield plating (most advanced - as per the GNL book) take over as the preferred method - as you say due to its short-term existence on the surface of the coins.

https://www.forumancientcoins.com/h...%20coins.pdf
Pillar of the Community
United States
2509 Posts
 Posted 05/10/2022  10:28 am  Show Profile   Bookmark this reply Add thq to your friends list Get a Link to this Reply
The instability of Bolivar's 1810-1820 New Granada Republics is fascinating to me. Your poorly plated copper Popayan 8R exemplifies the unstable period very well.

My favorite biography of Andrew Jackson is Remini's. He spent a lot of time in Spain studying period material, and kept running across the name of the hated Andres. One of Bolivar's great inspirations.
"Two minutes ago I would have sold my chances for a tired dime." Fred Astaire
Pillar of the Community
United States
1679 Posts
 Posted 05/10/2022  8:26 pm  Show Profile   Bookmark this reply Add realeswatcher to your friends list Get a Link to this Reply
John, I've never seen any of these Popayan copper issues (the 8R or the more common 2R, of which a number of high-grade examples exist) with any semblance of silvering. I see where it looks like that in the auction pics, but I think that's a combo of uneven tone around the devices after the noted cleaning and the lighting of Sedwick's pic. Compare to the (lousy as usual) NGC pics:
https://www.ngccoin.com/certlookup/.../NGCDetails/

Keep in mind, this is a tiny coin... nothing close to the size of a normal 8R. It's in fact closer to the size of a typical colonial 1R! No one was being fooled into thinking this was anything more than token coinage.

Here is a lustrous UNC example of the 2R denom. with a decent amount of Red remaining in the protected areas. That's essentially what the surfaces should look like:
https://auctions.stacksbowers.com/l...s-65-bn-PCGS

Pillar of the Community
United States
1553 Posts
 Posted 05/10/2022  9:56 pm  Show Profile   Bookmark this reply Add colonialjohn to your friends list Get a Link to this Reply
Sometimes acetone if used on copper can white the surface of copper in this manner but nothing like the over-abundance of the Stacks/Bowers piece - this post is just an alert. NGC photos still show the whiting however the coin is STILL in route from Sedwick. All high end examples passing through Heritage and Stacks/Bowers get slabbed and these are heading toward $1,000 in grades of AU or better and are few and far between. Perhaps somewhere ... someone having a high end raw example can do some surface testing. Not sure if I am going to break it out - keep the NGC label in the flip and have it tested - perhaps just with a XRF gun for FREE. Silver on the surface of this example - if greater than 1% - would show the presence of Ag was INTENTIONALLY added and not from any geological ore source and/or indirectly from the copper blank production process. I may proceed in this direction. If present (silver) who put it there? Will decide when I get the coin under a stereo microscope. JPL
Pillar of the Community
United States
1553 Posts
 Posted 05/13/2022  11:59 am  Show Profile   Bookmark this reply Add colonialjohn to your friends list Get a Link to this Reply
Received the coin today. I am 100% certain this is silvering and specifically mercuric silvering having seen this effect on copper hosts but of course strictly on counterfeit issues of debased metal host coins of multiple countries/denominations - many XRF verified with a vacuum chamber XRF device. I decided not to break the coin out. This whitish film has caused a non-homogenous surface and when an NGC grader sees a non-homogenous patina on any coin surface its tagged CLEANED - of course <BG>. It's OK - I am fine with it as I suspected all these factors prior to bidding. The reason I am not going to break it out is an inferior XRF gun may detect Ag but can not detect mercury - only a top end XRF device which has a vacuum chamber can confirm the quantitative values of both silver and mercury. Being retired I am just not in the mood to pay my go-to laboratory another $400/hr. analysis. Although based on realeswatcher's comments and some other high end AUs in Stacks/Bower's & Heritage's databases and one sole MS62 examples most have no silvering. This then leads me to conclude that this very short term emergency issue obviously just created to have some form of hard currency to pay the military may have been silvered in a post mint scenario - perhaps to further there ease into circulation after striking and leaving the mint in question being a high denominated 8R strictly made of a copper alloy. A very interesting piece which unquestionably requires more historical research moving forward. Since Hg/Ag films as previously described have tested to be AROUND 8mm thick did some get silvered to ease their circulation, on lower graded pieces is the silvering worn off but still detectable or is all this a post-mint phenomenon to have them be more accepted? BTW the NGC # is 6442565-040 and the NGC label reads: 1813 Columbia 8R Popayan KM-B3 AU Details Cleaned, Bernal Collection. This was lot #1644 in the recent Sedwick Sale. An incredible genuine example. I am in no way suggesting its counterfeit due to its silvering. 100% genuine!
Edited by colonialjohn
05/13/2022 12:10 pm
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