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 Replies: 7 / Views: 456 |
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New Member
15 Posts |
Hello
So I received a coin I purchased.
I alway test my silver coins upon arrival as low value fakes are rarely made with real silver.
I tested the weight and diameter and did a ping test
Diameter 26mm
Weight 5.08g
The weight and diameter is within limits and it passed a ping test.
However a magnet is sticking to it. The correct purity is 52.1% silver.
I have never seen a fake coin pass a ping test when the weight and diameter is within limits.
Did the Prussians use an alloy that contains a magnetic metal?
I am thinking of getting it XRF scanned to find out the exact make up of the alloy.
Thank you in advance
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Moderator
 United States
32709 Posts |
@blue, please post a pic of this coin as that may very well help. Additionally, you may have a heavily silver-plated fake. Please perform a specific gravity test and let us know what you find. Thx.
"If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz
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New Member
 15 Posts |
See attached photo. I don't believe a heavily plated silver coin would pass a ping test calibrated to the size and purity. I don't believe it would produce the required sonic frequencies. (In the past the app has offered a small reward if I can find a coin that can do so) It must be have Nickel or something mixed in the silver alloy. When I get a XRF scan, I'll post an update of the exact alloy composition  |
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New Member
United States
8 Posts |
4 German groschen
Composition Details:
521/1000 Silver .0895 oz. ASW, 479/1000 copper alloys
Per an online source
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Moderator
United States
32709 Posts |
Ok yes I'm looking forward to seeing the XRF analysis. Thx for following up with us when you have that info!
"If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz
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Moderator
Australia
16181 Posts |
What kind of magnet are you using? One of those super-powered rare earth magnets? I've found that an awful lot of things that "aren't supposed to be magnetic", like ancient bronze coins, will stick to one of those. Whatever alloy they're made of, it is very faintly magnetic. Not enough to be attracted to a refrigerator magnet, but plenty to be attracted to a rare earth supermagnet.
The official alloy for these coins would most likely have been "52.1% silver, and 47.9% whatever bits of base metal happen to be lying around the mint that day", not necessarily diluted with pure copper.
Magnetism is a strange and unpredictable property - it is not necessarily additive. It's entirely possible to take several pieces of metal that are not themselves magnetic, melt them all together, and create a magnetic alloy - that is, after all, what happens with rare earth magnets. You can also take magnetic metals (such as iron and nickel) and alloy them to create alloys that are completely non-magnetic (such as cupronickel). So it's entirely possible to have two otherwise identical-looking and genuine 4 groschen coins, and one will be magnetic and the other not. I have one of these coins; I'll test it later tonight and see how it reacts to a supermagnet.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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Moderator
Australia
16181 Posts |
Mine is dated 1805, and isn't attracted to a magnet. Doesn't have much of an eddy current effect either.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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New Member
15 Posts |
I got it scanned today at the local bullion store. The attached image says Ag 60.7 Cu 36.5 Pb 0.6 Zn 0.5 The very small amount of Zn mixed in the alloy is making it magnetic. Or as SAP mentioned the mix of different elements creating magnetic effect. At least it's genuine coin (a worn slick one) 
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Replies: 7 / Views: 456 |
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Posted 11/03/2024 5:02 pm
