They're useless as dice because they have that hole in the corner and another in the corner diagonally opposite. Strangely, though, as you can see from the picture, they're not identical. Furthermore, the one on the left isn't even balanced, in that adjacent to the 1 is the 6 that should be opposite it (adjacent to the 3); the die on the right is, however, balanced (albeit right-handed, rather than the left-handed standard for British dice).
OK, so I can see that someone might want to make dice with holes in to use as some kind of jewellery component, but why make them with two different patterns? And why put them in Christmas crackers?