Is there a fool-proof way to tell if a proof/mint set has been opened?

[bsshog40]

Short of throwing them on the floor and listening carefully how could you tell?

Simple, easy method. Take the set out of the box and lay a single layer of tissue paper paper over the set. (Kleenex or toilet paper. Paper towel is too thick.) Copper-nickel clad coins will appear as gray circles. Silver coins will appear as white circles. If you wish, use another set with known clad proofs as a control. Once you see it you will be shocked at the difference in the color.

 

That's a pretty neat trick there Condor. I just tried that with my 99 proof sets and tada, the silver set was whiter than the clad! Thanks!

[rrantique]

Short of throwing them on the floor and listening carefully how could you tell?

Simple, easy method. Take the set out of the box and lay a single layer of tissue paper paper over the set. (Kleenex or toilet paper. Paper towel is too thick.) Copper-nickel clad coins will appear as gray circles. Silver coins will appear as white circles. If you wish, use another set with known clad proofs as a control. Once you see it you will be shocked at the difference in the color.

 

Wow ,simple as going to the "Throne" Thanks Condor

[halfpint]

Short of throwing them on the floor and listening carefully how could you tell?

Simple, easy method. Take the set out of the box and lay a single layer of tissue paper paper over the set. (Kleenex or toilet paper. Paper towel is too thick.) Copper-nickel clad coins will appear as gray circles. Silver coins will appear as white circles. If you wish, use another set with known clad proofs as a control. Once you see it you will be shocked at the difference in the color.

 

That's a pretty neat trick there Condor. I just tried that with my 99 proof sets and tada, the silver set was whiter than the clad! Thanks!

 

 

now you gotta hope they don't 'milk spot' after the experiment.

 

 

[Conder101]

Now for the question, who can explain why it works? (I already know. And I've even explained it before but it might not have been on this forum.)

[bsshog40]

[rrantique]

I think it has something to do with the ambient light diffused by the tissue.