1999 d dime error?

[CmonManggg]

Can someone help me out with this? 1999 d dime, looks like missing partial clad layer, die clash, has some doubling on the reserve could be machine I dunno, and a die crack on the right side of the torch. Got a lot of different angles of pics, please let me know what you think Thanks!

[CmonManggg]

More pics

Here are more pics and also looks like another eye above the eye? thanks!

[wavysteps]

Your dime has been subjected to a chemical reaction that has caused the copper atoms to be more prevalent at the surface of the coin than the nickel atoms. This is commonly seen in dimes and a bit less frequently seen on quarters.

The one method of determining if the coin is missing a clad layer is to weigh it. Example; I have a SBA dollar that is missing the reverse clad layer. The coin should weigh 8.1 grams, but it doesn't since the clad layer is missing; it weighs 6.05 grams.

BJ Neff

[diamond]

I don't think there's been any movement of copper atoms. I think the coin is simply stained and discolored.

[wavysteps]

Mike - The atoms do not move. Since the surface of the coin is composed of 75% copper atoms and 25% nickel atoms one would think that the prevalent light reflectors would be the copper atoms (in the red / yellow spectrum). However, this is not the case. It is the nickel atoms that reflect the light (in the blue / green spectrum) giving the coin its color.

If there is a chemical reaction applied to the coin, such as corrosion or exposure to reactive substances, that light reflection is deterred in the nickel atoms and the copper atoms start to become the predominant light reflectors. This gives the coin a dull reddish coloration.

So, in actuality, the atoms do not move (atoms are in a constant state of motion, but in this case they are not migrating). It is just the ability of the atoms to reflect light that is affected.

I guess I did not explain my meaning of prevalence in the first explanation.

BJ Neff

[diamond]

It's an interesting concept. Would you be able to provide me with some references so I can explore this further?

[CmonManggg]

thx for the info guys, I have a few dimes like these. (nothing special then?) by the way do u see any die clash?

[wavysteps]

The information on why cupronickel is a silver color is basically very sparse. Even so is the explanation of why "German silver" (60% copper, 20% nickel and 20% zinc) is the same way. It may have to do with the hardness of the material and since nickel is higher up on the Mohs scale than copper this maybe the clue.

Silver color is defined as a metallic color tone of grey. Since nickel is harder than copper, the nickel's atoms may absorb and re-emit more of this grey tone than the reddish tones of copper.

"Copper has a strong absorption at a slightly lower energy, with orange being most strongly absorbed and re-emitted. In silver, the absorption peak lies in the ultraviolet region, at about 4 eV. As a result, silver maintains high reflectivity evenly across the visible spectrum, and we see it as a pure white. The lower energies (which in this case contain energies corresponding to the entire visible spectrum of color) are equally absorbed and re-emitted."

This may explain why cupronickel and "German silver" appear as such, because the nickel atoms re-emit stronger light wave energy than the copper atoms.

As with any stain, be it corrosion, patina, toning or such, the surface layer of atoms are the ones affected. These are the atoms that make the object colored. The actually structure of a given atom in the surface of the metal is not the concern, but what lays on top of that surface metal atom is.

For argument sake, lets say that the nickel atoms form a layer of nickel oxide on its surface of our object. This oxide will show as a green (not verdigris) or black colored stain, which alters the appearance of that metal. This can be applied to the reddish "stain" seen on the coin presented.

If for some reason the ability of the nickel atoms to reflect light back from the ultraviolet region is hampered due to some chemical reaction that forms a layer of different material over those atoms, then we can look at the copper atoms on the surface of the cupronickel as the source for most light in the red region to be absorbed and reflected back. This will make the stain appear as red or coppery color on the surface. Once that layer of deterrence is removed from the nickel atoms, the object will return to its normal color. This is typically seen in polishing off the blackish patina seen on oxidize silvery.

The last question remains; "what is the chemical reaction that took place to hamper the reflection capabilities of the nickel atoms?" That would be very hard to answer not knowing the history of where the coin had been.

BJ Neff