Determining if coin is silver or copper-nickel

[curtisbalvanz-migration]

New Forum member here.

 

I have been collecting silver coins from around the world for close to four years now. Most of the time, I have tried to avoid coins that were minted in both silver and copper-nickel - unless a Certificate of Authenticity was included.

 

I have been able to acquire a silver coin from every country in all the continents except Africa (still need a coin from nine countries there). I also have a coin from several island countries ("Oceania").

 

Needless to say, it is getting harder to avoid considering coins from the few remaining countries needed to complete my collection that have both silver and copper-nickel versions.

 

How can one tell the difference? I have a coin that I know is copper-nickel, but it is a "frosted" Proof coin that looks as nice as any silver Proof coins that I have. I also have what I suspect is a copper-nickel coin that was sold to me as silver Proof, but it does not have the "frosted" appearance of other silver proofs.

 

Sometimes I can find similar coins on eBay (that have certificates), which will help me to determine if what I have is silver or not.

 

Other than that, how can I determine a coin's composition if I have one that I am unsure of?

 

Best regards,

Curtis

[Stanley]

I believe the only solution would be to research your series.

Knowing the weights, measures, history as well as the minting process of each series.

[pendragon1998]

For those who have good hearing, you can flick a coin with your nail or put it on-edge on a table and then release it and listen to the sound it makes. Silver makes a bell-like ringing tone while clad coins make a less-musical 'clink'. Just for fun, try this with a silver half and a clad half. The same trick works for distinguishing copper cents from zinc ones. Obviously depending on coin quality this may not be the best way to assay it. Weight is generally the best and safest way to go, but you must find a quality scale.

[Zoins]

Can you say which coins you have questions about?

[curtisbalvanz-migration]

Can you say which coins you have questions about?

 

The one that I was referring to is a Sierra Leone 1974 1 Leone.

 

K&M's SCWC lists both the silver and copper-nickel varieties. They don't list the weight of the copper-nickel coin, so I can't use "weight" to distinguish which one I have.

 

The silver coin was only minted in Proof quality, the copper-nickel one was not. The one I have could certainly be called Proof but it is not frosted like most other proofs I have are. I also have a few other coins in MS quality that I originally mistook for proof that look as good as this one does, so I can't really use "looks" to distinguish what I have either.

 

I've seen another one of these Proof coins on eBay that came with a Certificate of Authenticity. I couldn't tell by the seller's photo if they were the same but he did say that his was not frosted either.

 

I'll try the "ring test" that was suggested earlier to see if I can tell the difference. This doesn't sound very "scientific" but, hey!, if it works, it works! :-)

 

Regards,

Curtis

[satootoko]

You don't need to know the weight of KM#26, the cu-ni version, as long as you know that KM#26a, the coin silver version, weighs 28.28g.

 

If your coin matches that weight, within .02g either way, it's silver. If not, it's cu-ni.

 

(If I have my relative weights straight, the cu-ni will weigh less than the silver, but in any event it will have a significantly different weight.)

[TwoKopeiki]

The best way would be performing Specific Gravity testing on the coin. Silver has a different SG than cu-ni alloy.

 

It requires a bit of set-up, but once you have it going - it should help you with determining low-contest counterfeits, etc.

 

~Roman

[Conder101]

Here's a quick down and dirty method. The tissue paper test. Get a known coppernickel coin of roughly the same size and finish (shouldn't matter if it isn't exact) and put a layer of tissue paper over both of them. The coppernickel coin will show through as a dull gray circle. A silver coin will be a white circle. The reason is because silver is the most reflective of all metals reflecting 95% of the light that falls on it. Copper nickel reflects much less. So almost all the light that gets through the tissue refects back off the silver while most of it is absorbed by the coppernickel.

[IlikeZARcoins]

I normally drop the coin on a concrete surface from a height of about 6 feet.

 

I can then tell the composition of the coin by the 'cling' or the 'clang'.

 

[Stanley]

I normally drop the coin on a concrete surface from a height of about 6 feet.

 

I can then tell the composition of the coin by the 'cling' or the 'clang'.

 

[satootoko]

I normally drop the coin on a concrete surface from a height of about 6 feet.

I've found that the sound from a full 2 meter fall onto a ceramic tile floor is a much more accurate indicator.

[IlikeZARcoins]

I normally drop the coin on a concrete surface from a height of about 6 feet.

I've found that the sound from a full 2 meter fall onto a ceramic tile floor is a much more accurate indicator.

 

I just knew that someone would have a much more accurate method.