Need Help!! 40% Silver 1974 Ike?

Hey, So the weight is closer to clad then it is to silver. Infact the clad coins are weighing higher then the one is question. This is my old digital scale but regardless of calibration, clad shouldn't weigh more then the silver planchet. Ill get more precise with a digital caliper tomorrow. While weight is a great test, I've learned from the past that when it comes to mint errors, esp ones with very little to compare too, weight shouldn't be used to debunk. but does bring my excitement factor down. I suppose it will come down to NGC. I'm sure they will use an expensive non mutilating test for composition. Does anyone know if they silver planchets have more reeding then the clad?
Matt

You might try taking a razor blade and make a scratch in the reeding on the rim above one letter on the edge of the coin. If it is plated, then the copper would show through on that area. I do this on the plated quarters to show they are plated. This way it doesn't damage the faces of the coin and you will find out it it was plated.

The tissue test works on uncirculated coins. It they are toned/off color, the are harder to tell. This even works in an album. You can see which ones are silver without removing the coin from the book.

But the above test will tell you quickly if it was plated without ruining the coin.

tissue test is good but can be fooled by plating. Weight can be inconclusive because the tolerance ranges of the clad and 40% almost overlap on the Ike dollar (They DO overlap on the quarter and half dollar) The next test (before you do a destructive test like scratching it or using acid on it, or spending a lot of money sending it to a TPG) would be to do a specific gravity test on it. THAT should be conclusive if done carefully. Clad SG would be 8.92 and 40% is 9.53 Tt is pretty easy to get accurate to one decimal place plus or minus .1 With care and good equipment you can pretty much nail that first decimal place and get the second to +/- .05

lightly Scratch a corner on your acid stone and test using 18 k acid.
What color does the silver rub turn on the stone?

And if it shows as silver it tells you nothing because all this destructive test does is test the surface so it can be fooled by plating.

Yea, acid would be my last resort. I think NGC will be the way to go.

Clad weight 22.68 grams
Silver clad weight 24.59 (From ' Red Book')
The mintmarks are 's' for the silver clad examples.

You could send him an email.
John1