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 Replies: 16 / Views: 2,974 |
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New Member
United States
43 Posts |
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Pillar of the Community
United States
2003 Posts |
I had to subscribe to this thread. Hopefully SwamperBob will weigh in on this since he is quite knowledgable with these.
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Pillar of the Community
Canada
5239 Posts |
@jimmybob96, in case you are wondering, Swamperbob is an expert and aficionado of 8 reales, especially the counterfeit kind. I can safely say, though, that the 25 grams weight of the coin virtually guarantees that it is not genuine.
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New Member
 United States
43 Posts |
@oriole I am aware of swamperbob, as well as the fact he published a book on fake 8 reales too if I remember correctly. On another note, I figured there was no way this was genuine at 25 grams, if it was legitimate and weighed that much the coin would be bald on both sides. As for whether this was made a long time ago, or was actually used in trade and is actually made of silver, remains to be answered. I figured I would consult this forum before doing something like having it XRF/Sigma tested for silver content, and whether I should even bother doing such a thing. Thank you for the information though, have a good night!
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Pillar of the Community
United States
2003 Posts |
JimmyBob, you could try a specific gravity test yourself before attempting an XRF. After all, you have a scale and a cup of water and that is free.
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New Member
United States
43 Posts |
That's definitely going to help MisterT, if I recall that process has to do with dividing the original weight and the weight of a zeroed out cup of water after inserting the coin. I must admit, that scale is not mine and was used when I popped by an antique store (I didn't get the coin from there). I do have a food scale, but that thing sucks because it can't even do decimals for grams. I will post an update when I'm able to accurately do a density test. For now, I will voice some more observations in case they're helpful. I measured the diameter with a caliper and the largest measurement I got was 39.11 mm, lowest was around 38.78 mm. Which according to Numista is about right (39 mm). The coin obviously isn't perfectly round and I believe that the average diameter is correct. Interestingly Numista doesn't have a thickness associated with the Mexico City Charles IV 8 reales series (1791-1808), but I measured the thickness to be no less than 2 mm. Comparing that measurement with the Charles III Mexico City 8 reales (1772-1789), that measurement appears to match up. Lastly, the coin has been obviously cleaned and has developed some black spots on both sides.  |
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Pillar of the Community
Canada
5239 Posts |
We will wait for Swamperbob to respond.
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Pillar of the Community
United States
2003 Posts |
The SG test can be tricky. First you need a scale that can read to at least two decimal points. You get a dry weight of the coin and record the reading. Then you need to fill a small container with water, place it on the scale and zero the scale out. Then you have to suspend the coin by a thread into the water without the coin touching the bottom or sides and record the "Wet Weight". Then it is just a matter of dividing the wet weight into the dry weight. Silver should be about 10.33. Readings in the 9's are closer to copper. It can be quite tricky and may require several attempts to get it right. Errors as little as .1 gram will give you false readings.
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Pillar of the Community
United States
1913 Posts |
SG testing has been an essential part of my collecting because I collect non-genuine coins and then seek to buy the authentic coins for comparison. I began by trying a number of methods using a variety of devices. I was able to get a good enough result at first only on the largest coins. Not possible to get the good results on the lighter coins until I popped for the big bucks. There are many choices, but this one is mine. It has an underhook perfectly suited for suspended measures out and then in water with a simple setup.  Edited by Albert
12/20/2021 06:13 am
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New Member
United States
43 Posts |
That device looks REALLY expensive, also, is advertising products allowed on this forum? I thought moderators usually warned you about posts like above. I understood specialty devices probably existed for doing SG tests, but this is coming from somebody who doesn't wanna spend 4 figures on a device like above. MisterT, I will try my best to get a good result, as that information will be important in determining if it's possibly silver. Might take me a few days to get my hands on an accurate scale and get around to testing it during the holiday season.
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Pillar of the Community
United States
2003 Posts |
Albert, that is a fine setup being able to read to four decimal places. What does something like that cost? JimmyBob, You can still experiment with and get accurate results with a two decimal place scale. Just takes lab like precision and patience. Even a breeze from a fan can disrupt the readings. I don't get to perform this test very often but when I do I have found that the string which suspends my coin also had a "Wet Weight" of .01 gram by itself so I had to deduct that from my wet reading. I was able to determine that a Trade dollar I had in my collection for over 30 years was a counterfeit using the SG test. I had to perform it several times to see if I got the same readings. Once I was confident in my testing, I determined that it was closer to copper than silver. I filed the reeded edge and exposed a copper core proving it was fake. The SG test does work. |
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Moderator
 United States
188213 Posts |
 to the Community! |
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New Member
United States
43 Posts |
Thank you for the warm welcome jbuck! To post an update to this thread, I likely won't be able to get an SG result until on or after Christmas day. I may try my hand at calling some local pawn shops or jewelers to see if they have non-destructive methods of testing for precious metals that won't set me back any money. I noticed that I omitted this bit of detail from my initial post, but I must disclose that this coin is not magnetic, I tested with a rare earth magnet. I, of course, wouldn't be attempting to do an SG test if it was magnetic in any capacity.
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Pillar of the Community
United States
5362 Posts |
Sorry it took so long, but other members have responded correctly. The coin is definitely a fake. The other question you ask regarding the type is more difficult to assess.
From the edge, at first glance, I thought it was likely contemporary (CCC) but from the faces, I would tend to think it is a silver counterfeit (Class 2 in my book). However, the weight being so low makes a Class 2 counterfeit very unlikely.
So, I looked a bit closer - the corners of the coin where the edge meets the faces seem to be ground to remove the join. This is usually a feature of modern recently made Numismatic Forgeries. It is due to the nature of a centrifugal casting.
I realize this takes us full circle, but with the increasing value attached to CCC types, it concerns me that a forger could be making copies of older counterfeits. I am not sure as it is impossible to tell from pictures alone, but I would love to know which.
I can suggest further testing I would perform if the corners are not ground down.
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New Member
United States
43 Posts |
Thank you for taking the time to respond to my questions swamperbob. That is definitely unfortunate, the only thing I was really banking on was that it may possibly be a Contemporary counterfeit and have some collect-ability. From what I understand, numismatic forgeries are more recently made with the intention to defraud an individual. Looks like I didn't pay enough attention to details when purchasing this off ebay. What's worse is I bought two 8 real coins from the same individual, so now I'm 100% certain that one is fake too. I tried to do due diligence and bought from a seller here in the United States with a good review record, so I can't be certain this individual knew they were fake, but it's definitely suspicious. I'm going to see if there are any possible avenues to get a full refund whether through the seller or ebay. I can make a separate post about my 1778 8 reales if you're interested in looking at it. I understand this sort of thing happens to most coin collectors, so I will learn from this experience and definitely be more meticulous if purchasing this series of coin from ebay. They didn't even have the weight posted, so I practically invited this upon myself without knowing how commonly faked these coins are. |
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Pillar of the Community
United States
5362 Posts |
jimmybob96 I take from your reply that the edges of the coin are in fact ground down. That would be fairly conclusive proof that the coin was modern. Otherwise, unless you have done a density test or XRF test why have you decided to return it?
I tend to keep even Numismatic Forgeries because every fake has some information to transmit. Even if it is what to avoid in the future - you do need to know how to avoid other similar coins. You did not say how much you have into the coins or why you believe the second coin is fake as well.
I would like to see that one as well and hear your reason for returning it.
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Replies: 16 / Views: 2,974 |
Posted 12/19/2021 5:29 pm
