Silver content of 1967 Canadian coins

I know that in 1967 the Canadian mint minted dimes and quarters in 80% and 50% silver. Does anybody know how tell the difference between them?

 

Log in or Sign up to hide this ad.

The Charlton catalogue says the two types are not distinguishable by eye so I'm not sure how to tell the difference.
As a matter of interest some .500 silver were also minted in 1968

 

I would guess you could tell by weight. It's strange they reduced the silver content due to rising costs of silver at that time instead of eliminating silver entirely.

David

 

I checked that, the weight is the same.

Bill

 

I bet you can tell by the toning. Looking at UK coins from 1919 and 1922 you can tell which one's sterling and which one's not as they tone. The lesser silver content ones tend to be greyer.

 

Drop them along with a silver pre-66 and a silver '68 for the same denomination and compare the "ping". Nobody really cares anyways, they're simply treated as .650 silver for bullion purposes.