What year did Canada stop making silver coins for circulation?

Until 1966, Canadian dime, quarter, half dollar and dollar coins were made of 80% silver. In 1967, the cost of silver increased, so the Royal Canadian Mint cut back on silver content in quarters and dimes. The half dollar and dollar remained 80%, but the dime and quarter averaged 65%. In 1968, silver was cut back in Brunswick and Saskatchewan quarters of the Queen and Caribou should both be upright when flipped side to side. There is an error where instead being upright they are inverted, with one facing downward. These inverts start at $100 each.