Canadian Silver Coins- 80% vs 50%
 

Hello to all out there! A question- I know that Canadian dimes and quarters in 1967 were minted in both 80% and 50% silver, but does anyone know how to tell the difference? I've bought a few recently, and can't tell which they are.

Re: Canadian Silver Coins- 80% vs 50%
 

There is no visual way, and Charlton gives the exact same mass for each type to 1/100th of a gram. Copper and silver are both great conductors (the remaining 50 or 20 percent of metal in the coins is copper), so I doubt there would be a measureable difference in the resistance.

Possibly you could do some kind of scratch test, on each and every one. You'll have to find some nitric acid somewhere and two Canadian coins you know to be 800 and 500 fine for comparison.

I personally just assume that the are all 500 fine, and pay accordingly.

Re: Canadian Silver Coins- 80% vs 50%
 

Actually, it's not physically impossible, it's only that the volume will change slightly- since the densities are different as you say. Think of it this way- mix together 1 oz. Ag and 1 oz. Cu (50% silver), then weigh out 5.8319 g and make a quarter out of it, just like you could do with the 80% mixture.

That is an interesting link, but the "Standard Catalog of World Coins" by Krause lists both the 50% and 80% at the exact same weight (5.8319 g).

Re: Canadian Silver Coins- 80% vs 50%
 

I didn't beleive they were the same weight when I first read the numbers in Charlton, but I took a bunch of '67 cougar quarters (12 or so... I can't remember exaclty - it was 10 years ago!) and weighed them. They were all the same weight to 1/10 of a gram. I figured they couldn't all be 800 fine, so I accepted the book's numbers after that.

I'll give it another shot. I have more quarters and a better scale now...

I got a 500 fine and 800 fine dollar out to compare the electrical resistance (they were the same to the accuracy of my cheap multimeter) and was going to compare the weight - the only problem is that they made the 500 fine dollar a bit larger! It's a pain.

I think maybe they increased the thickness of the 500 coins to keep the weight the same. Hopefully I have a '68 quarter around somewhere to get some definitive numbers from...

Re: Canadian Silver Coins- 80% vs 50%
 

thank you for raising this question, this is important to know as silver price gets higher

Re: Canadian Silver Coins- 80% vs 50%
 

I think it's pretty safe to say that all
the 1967 coins you have are of the 50% variety