There is absolutely nothing different other than where it was mined.
You can find H I2 diamonds in Canada and D IF diamonds in Africa. You can put 50 or 100 or any number of facets on any diamond you want.
Some jewelers (Peoples/Mappins/Samuels/Rogers, and many more) have a Canadian brand that uses a higher quality diamond than their other diamonds, and/or has more facets, so of course that diamond will be priced highest and look the best in that particular store.
schadenfreude13: De Beers owns at least two diamond mines in Canada (Snap Lake, Victor). In addition, historically De Beers buys rough from other diamond mining companies, including ones in Canada and Russia.