Bruce R. writes: Hi! The Krause World Coin book lists Canadian dimes and quarters in 1967 as being minted in two types; 50% and 80% silver, and in 1968 as two types; 50% silver and 100% nickel. Unfortunately, it does not mention how to tell them apart! Any clues for those of us who have some from these years? Thanks!
Many years ago, I worked for a firm that wanted to make face value bags of Canadian coins. There is no visible way to tell, as the dies are identical and the alloy has the same appearance in both silver finenesses. The answer was to do a Specific Gravity test on each coin individually. This test is a ratio of dry weight to the coin’s weight in water (Remember the story of Archimedes?). I’m sure that it wasn’t cost effective (It seems that you could just assay a large number of them and get the net silver content that way).