The bible of Canada coins Charlton say 1987 -1.95 , 1988-89 - 1.75
In 2003 with the new effigy they go to 1.95 again.
They were not minted for circulation from 1997 to 2001. If you have one it came from a set.
regardless the weight does not change with thickness change. Mint wizards.
In 2012 they made a small change to the design and added a laser etched maple leaf to deter counterfeiting. Maybe a counterfeiter made a coin with the wrong thickness.
I don't know yet. The previous poster suggested this thought and then I start looking closer and saw the pearls on your coin are elongated in stead of round like on the picture of the coin page. But these are pictures of a 1987 coin, so you never know. I have several 1988's myself but I still have to check them. If the pearls on my 1988's are nicely round, I think your coin might be a fake.
Verweis : "ThePoet"Maybe a counterfeiter made a coin with the wrong thickness.
Indeed maybe. Shouldn't the pearls be nicely round? Not on the OP's coin:
I think that is an artifact of the photographic technique. Look on the obverse and how they go from round to elongated as you go around the edge. My 1989 definitely has round pearls.