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 Replies: 11 / Views: 1,324 |
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Valued Member
United States
75 Posts |
I bought a big lot of German Pfennigs and non-silver one marks the other day and while going through them I found the following two coins.... The 1924 D 10 Pfennig is obviously a minting error but the 1965 F 1 Mark...well.. has me puzzled. At first I thought this was post mint tampering but the more I look at it I start to think it isn't. The nickel coating on one side of the coin is missing. It is also missing on the rim and is present only on the Obverse side. I tried to take some good side shots to show you how perfect the line of transition from Nickel plating to non nickel plating is. If it was striped, someone took their time doing it right... I also posted a picture of what it SHOULD look like... Die crack on the reverse across the ears of wheat and then rim issues on the obverse... Large crack and looks like it is rolled over on itself.  Nickel plating is on the reverse but missing on the obverse and side  Side view of the coin  Another side view showing the reverse also  And finally... how it SHOULD look  |
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Moderator
 United States
23731 Posts |
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Pillar of the Community
Egypt
3470 Posts |
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Bedrock of the Community
United States
10045 Posts |
 the 10 Pfennig is a rim Cud and die crack.  The 1965 1 DM is solid cupronickel, not a plated coin. The coin may have set on something reactive that toned the copper that way. |
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Pillar of the Community
Spain
1361 Posts |
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Valued Member
 United States
75 Posts |
I am not sure about what is going on with the 1 mark... If you look at how precise the change is on the rim edge... just looks weird... I dipped it in acetone to make sure it wasn't something on the coin but as you can see it is still there, it is the coin metal itself... It ALMOST looks like the coin is Nickel plated on one side... as you said, these are a copper nickel composite.. just going off what it LOOKS like though... I thought about sending it off to a TPG to be looked at to see what they think. |
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Valued Member
Australia
432 Posts |
The 1DM looks like Red Oxide has been applied to it! BUT my guess is, that its been laying Obverse down in some sort of drain or pond or something and has come into contact with rust in sediment - you'd be surprised how much stuff like that can stain!
So yeah, you 10Rpf is a genuine planchet crack, but the 1DM is just dirty :)
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Pillar of the Community
United States
3098 Posts |
Yeah... cupronickle doesn't split after smelting, does it?
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Valued Member
United States
75 Posts |
Ok... lets say it was laying somewhere... it laid perfectly in, whatever it was, to the point that it got an exact edge around the top of the rim... I see what your saying but you gotta admit that the chances of something being that exact are slim... Just to make sure that something wasn't staining it, I soaked again in acetone AND gave it a quick wash in some light detergent. Still looks the same. Whatever it was in was corrosive... mystery to me but cool either way.
Edited by ASUTodd
03/03/2009 7:38 pm
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Valued Member
Australia
432 Posts |
You'd be surprised how easy it is to get this effect with a coin - if you ever get to see what things look like coming out a wishing well, you'll understand. I've seen coins that have landed flush on the bottom, then had a second coin land on top and to the side of them, leaving what looks like an UNC coin on one face with the other having a big cresent shaped stain across it.
And also, it doesn't have to lay perfect either (depending upon what sort of element is present in the water; is it sediment or in solution? in solution is much more pervasive than sediment as its part of the water, where sediment is just floating in mixture)! Sediment settles DOWN; in non turbulent and slow moving water this means it doesn't even creep under an object much. So maybe your coin spent some of its life in a wishing well or a drain?
Perhaps even the red is just 'red oxide' primer? The coin was laying on a piece of metal being primed and well, got painted! Its extraordinary what goes on in workshops when tradies get bored (a short list is - Oxy a coin face, cut a coin in two, grind the coin, punch the coin, drill the coin, plate the coin (with nickel, copper, even gold! its quite easy to NOT plate one side) and even use coins as spacers, shims and washers. Illegal as all this technically is, even I've been shown the effects of welding gear by demonstration on a coin!
But yeah, while this is not an error (and I honestly cant figure out what you would need to corrode the alloy CuNi250 with to get an Fe2O3 colour - it got to be a surface plating effect) its definately a coin to hold onto if you're interested in coins with interesting appearances (I've a whole folder of interestingly coloured and worn Australian Predecimal Copper)...
And Acetone wont remove metallic sediment; for things like Fe-based sediment, you may need to go as far as a Phosphouric solution, altho what the effect on the CuNi250 alloy is, I do not know! But I guess you got to find out what it is first; 99.9% sure its not a corrosive effect tho...
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Bedrock of the Community
United States
10045 Posts |
Cupronickel coins take on some interesting colors in exposure to soil and water. Although nickel doesn't tone, the copper will to some surprising results. I have an Iceland 10 Aurar with almost the exact same coloration. |
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Valued Member
Australia
432 Posts |
DVC - any idea's what caused your 10Aurar to discolour? I must admit, I am now interested in the chemical process, having never bothered to look into this on CuNi250 and Ni1000 compositions. Stuff like, is it in fact a result of the CuNi Alloy corroding in some manner or is it simply a deposit...
Science is fun! :)
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Replies: 11 / Views: 1,324 |
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Posted 03/02/2009 10:21 am
