1978 $100 Canadian 1/2 ounce GOLD proof coin With presentation box and COA This 1/2 ounce coin comes in a presentation folder. See pics for gold composition etc. The coin weighs 16.965 of 22k gold of which 15.551g is pure gold to make the coin a true half ounce of gold. Current 1/2oz bullion price is $924. My price of this 1/2 oz Gold Proof is $900 posted (within Australia).