Serious question

[Raralith]

Honestly, all the above ideas are great, but if you want to save yourself a lot of trouble, try a botique. Movado, Tiffany's, Cartier, etc... pretty much only carry high quality diamonds. Yeah, it's expensive, but you know it's high quality. If someone says ask your wife, "What a nice ring," all they need to reply is, "It's a Movado/Tiffany/Cartier," and most women would drool.