There are over 20 variations on the modern $100 Canadian Gold piece. Use this link to determine what coin it is.
There are two variations on the coin-
1976 had a '1/4 ozt and 1/2 ozt' gold version with the same exact design.
One weighs 13.34 g with a purity of .5833
Another weighs 16.97 g with a purity of .917 http://taxfreegold.co.uk/canadian100dollarscommemoratives.php