Blue Nile uses “display jewelry”
in their show rooms so what you see in the show room is cubic zirconia. You can’t see the diamonds before you buy. For the money I think Tiffany & Co. is the best option & you can see the exact diamonds that you will be buying.
Tiffany and Co requires you pay a huge markup for a brand name, when you could get the exact same diamond specs for a fraction of the cost - either from Blue Nile or a local jeweler.