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 Replies: 45 / Views: 2,863 |
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Bedrock of the Community
Australia
21788 Posts |
In the assumption of perfectly correct reporting by the OP,
there seems to be two possibilities to give the result of what we see in the pics
1. A 'mint sport', where there was a deliberate error created by a Mint employee of a struck through between two pieces of fabric.
Nevertheless, at this stage, I cannot completely dismiss the possibility that it is is a 'shed job', created by
2. impressing a fabric pattern, post Mint, onto a coin with an industrial press.
Further investigation required.
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Pillar of the Community
Canada
6244 Posts |
I will like to know the weight, because do not seem to be a Genuine coin. Please look at the compare photos. The original design and the OP photos.  |
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New Member
 United States
15 Posts |
Wow, just learned a couple new phrases. Seems like a lot of trouble to go to and not keep the coin (s). Not sure what more investigation I can do other than take to a dealer.
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Pillar of the Community
Canada
6244 Posts |
What it is the weight? If you has a good dealer could be an alternative and also to made you an XRF. All the fake 1964 Halves I saw was 925 Si and not 900 Si
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Moderator
 United States
96936 Posts |
Sorry I haven't gotten back til now, (Life got in the way). up above in one of my responses - there was an errant 'W' in there - just ignore that (my fingers got crazy)
Thanks for the new images. the angles of these marks are the same on both sides. For now, I'm just going to call them crazy roller lines - only because they follow the contours of the devices with no gaps where the device meets the fields. I think that these were on the planchet before the strike (just a huge guess here) As you can see the lines were worn off of the highest point of the devices on the obverse (the cheek area)
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Valued Member
United States
169 Posts |
I will throw my hat into the ring, I don't believe it is a planchette issue due to the fact coin press operates at 35 to 100 tons metric force when striking the blank. So if the planchette had this pattern to begin with I believe it would not show on the devices after striking since the raised rows on the coin are minimal. Since the devices do show some extra metal on top I would say it is due to metal displacement caused by pushing the coin thru a machine to created a brushed finish look (aka straight hair finish). The hairline grain could be created by polishing with a metal bristle brush turning on a wheel or belt that moves in the same direction. that is my theory, it is PMD, I could be wrong but I also would expect more confirmations of this type of coin in existence if it was a planchette issue. BTW most fabrics have a weave pattern which should show and a weight check could be helpful as @silviosi stated Edited by surfacewave
03/02/2023 10:41 pm
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Pillar of the Community
Canada
6244 Posts |
@ surfacewave:
The Dies are polish rotative and not with band machine. This it is performed manually in the special department and then before to go back to the production line it is approved and check by the QA. The modern coins, to day, is check by a special laser installation (security purpose I do not give the name). To day as before is not check just the surface quality but also the weight and all the diameters. Any small changes could required the adjustment of the presses and this will never be approved.
Edited by silviosi
03/02/2023 10:50 pm
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Moderator
United States
96936 Posts |
Quote:
I don't believe it is a planchette issue due to the fact coin press operates at 35 to 100 tons metric force when striking the blank. So if the planchette had this pattern to begin with I believe it would not show on the devices after striking since the raised rows on the coin are minimal Well, when we see other coin that display 'roller lines' they still present after the strike, even though the roller lines are imparted to the sheet of metal as it is thinned to specs. If you look back to the example that Silvio posted, they look like roller lines too but in a random pattern. Edited by Dearborn
03/02/2023 10:59 pm
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Pillar of the Community
United States
3207 Posts |
FWIW the lines are not perfectly straight, for example, they curve slightly between the R and Y of Liberty
my guess is tarnish from being stored for a long time within layers of fabric
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Bedrock of the Community
United States
25398 Posts |
Still waiting to see if an acetone soak had any effect on these "lines".
Inordinately fascinated by bits of metal with strange markings and figures
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Valued Member
United States
169 Posts |
@Dearborn:
Let see if I got this based on your last post, roller lines are present due to the process of the planchette thinning to specs, visible roller lines on the coin would only be typically found in the fields of the coin but the roller lines would obliterated due to the metal rising from the planchette during the strike. So does that mean that the strike was weaker than specified for that coin because roller lines are on top of the devices? If so, I would have to conclude that roller lines existing on the devices would be more apt to occur on larger coins which require more strike force. I appreciate the feedback it accelerates the learning process
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Pillar of the Community
Canada
6244 Posts |
Me I want a chime on the authenticity. My previous photos.
Edited by silviosi
03/02/2023 11:47 pm
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Moderator
United States
15469 Posts |
 to the CCF Curious coin for sure. It's not often that a coin comes along that our experts are uncertain about. Agree with silviosi that an accurate weight to 0.01 grams tolerance would help. |
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Moderator
United States
96936 Posts |
To the OP - Are the raised lines the dark lines or the silver lines?
Can you post up a picture of this coin (either side) at an angle (almost directly looking at the edge but still seeing the surface)?
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Moderator
United States
96936 Posts |
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Replies: 45 / Views: 2,863 |
First Page
Posted 03/02/2023 6:26 pm
