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 Replies: 10 / Views: 2,465 |
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Pillar of the Community
France
1591 Posts |
Hi, I'm suspect about the authenticity of this coin, mainly because of the bubbles on its surface (looks like a cast copy ...) The rim also don't look fine (not visible here - hard to shoot because of the coin size / height). Can someone confirm my doubts ?   Thanks, Mathieu |
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Pillar of the Community
United States
1666 Posts |
I don't see the bubbling on the surface you mentioned, but the pitting is often seen on coins that were sea salvaged. This one in fact looks like it was either dug or sea salvaged and then cleaned.
Overall the rim denticles and details are acceptable for this type. Some of the letters are unusually thick, especially at the bottom, but these coins are known to have many many die varieties. As long as the weight is correct I would not worry about it being cast. The weight on this one should be a bit under, probably around 0.2 grams, considering the condition.
I recently came across a 1799 Lima 8 reales that had spent time at the bottom of the sea. This coin was genuine, but weighed only 24.1 grams because one side of the coin that was exposed was eaten away, causing that part of the planchet to become very thin. This coin had some of the same visual features that your coin has.
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Pillar of the Community
United States
1801 Posts |
Numismat, I have to say I do not agree with your assessment, the coin does not look sea or land salvaged at all. I have seen many 1715 vintage gold coins pulled up from Spanish shipwrecks and they look pretty much like they did when they went down. Gold is a "noble" metal and does not corrode, the copper mixed in it will etch out but it will not leave "pits" like you see on this coin because the copper is alloyed with the gold, not sitting in large chunks within the coin. Silver coins on the other hand do corrode away, I have found dozens of coins so thin they cannot be identified (we call them razors after razor blades). Weight diminishes as they corrode so they are underweight as well. I have never found a sea salvaged gold coin underweight below normal tolerances unless it was extremely sand worn from being in the surf zone with a hard bottom where it could not bury in the sand which is what gold coins tend to do, they keep working their way deeper in the sand.
On this coin I don't like the look, I don't like the pits, I don't like the mushiness of the details. I personally would pass on the coin for those reasons but I think since MathieuMa already owns the coin he would be well served to do a SG test on the coin and determine if it is .9010 fine gold.
Edited by jfransch
05/01/2011 6:49 pm
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Pillar of the Community
United States
1666 Posts |
This one actually does look like ones that was exposed to "tumbling" in sand. I know gold will not be diminished by simple exposure, but a cleaning or erosive forces in nature will take off a bit of weight.
The reverse crest looks mushy, I agree, but the portrait and rim denticles look good. I only have pictures of a couple examples readily available to compare though.
Is it possible to get a close-up of the pits? It's hard to tell if they are the result of trapped gasses from casting or just dings from contact.
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Bedrock of the Community
Australia
21786 Posts |
I am not familiar with these coins. Is the style OK? (especially obverse)
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Pillar of the Community
 France
1591 Posts |
I'll take closer pictures today, and will try to do my first SG test :)
Will take some time to come though, I got peoples at home today !
Thanks :)
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Pillar of the Community
United States
5362 Posts |
I don't do much with small gold coins - but I don't like the looks of this one. To me the holes look like jerk punches - little test dings you can do with an awl. They do not really look like bubbles. But the details are all too mushy looking. The coin has had a tough life if it is real. Regarding SG on this one. That will be very hard to measure - this is a small volume to measure by water displacement. I am pretty sure you would need an analytical balance to do it. This coin only weighs 3.37 grams or so and using an SG of roughly 17 the volume would be in the vicinity of 0.2 cc. Far too fine a tolerance for me to tackle and be 100% comfortable with my results - especially given all those air entrapping dings.  |
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Pillar of the Community
France
1591 Posts |
Hi, Didn't had time to do the SG test, mostly because I thought I was going to the hospital tonight (pregnant wife near therm at home) :) And as you said, that coin will be hard to test - between the holes which will keep air bubbles and the small weight ... I had time to take some pictures tonight - but that's hard with this small coin and without a macro lend :D I turned out with one proper side, the edge and the other side will need other tries :/  (click for poster size) The coin's weight is : 3.19g Edited by MathieuMa
05/02/2011 6:47 pm
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Rest in Peace
United States
9104 Posts |
someone's wires are crost. one poster sez 3.37g, the OP sez 16g. seems it's solid gold, if nothing else.
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Pillar of the Community
United States
5362 Posts |
The large picture shows the "dings" clearly. I do not see bubbles at all. It looks like a jewelry piece that has had hard use. I see nothing that screams counterfeit at me.
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Pillar of the Community
France
1591 Posts |
biggfredd : was late yesterday, my scale was set to ... carat ... :D Fixef that ;)
Yep, by looking closer the coin looks 'fine' - at least technically speaking. I think it could have mounted as well, considering the rim (which I couldn't put on picture - too small).
Thanks !
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Replies: 10 / Views: 2,465 |
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Posted 04/30/2011 8:48 pm
