Hi didi,
Congrats on such a wonderful decision. I am an antique jeweler and it is very important to buy somewhere you really trust. Of course Tiffany and CO. is super famous but I am wondering why you would only buy there? Do you just love the store--I do--but I never buy there. You are paying over 40% more for the name. I don't know if you realize that all large diamond wholesalers buy diamonds from the same place.
With that said--look for clarity first, than color, than ct. size. Unless you want a big hunk of a diamond and don't really care about color and clarity. D,E, or F is colorless--the best, IF (internally flawless) is the top. From there, color and clarity go down a bit. Like G, H, color are really great, but may pull slight yellow. Not noticable to the naked eye but with a special light, loupe, or comparision diamond you may see it. For clarity, VVs, VVs1-2 etc are still great but again will show a tiny flaw. This may only be visable to the most expert eye.
So, thats my take on diamonds. I would shop around and not just choose Tiffany for the name. Yes, you can always trade up there, but many other fine jewelers have the same policy with far less overhead and markup. Sorry all Tiffany addicts.
I have a pre 1940's Tiffany jewelry collection. I loved their early jewelry. I guess I love the sentimentality and uniqueness of the old pieces. I always think Tiffany was so expensive it was given to a great love, and kept for that reason until the grandchildren needed money or didn't like the style. I am an old soul.
The way you reference VVS 1 and 2 makes it sound like you could possibly see a flaw.......they are just a step below IF......most likely the only way anyone would see a flaw in a VVS stone is if they were looking at it under a microscope. I have a VVS stone that has only 1 needle inclusion that you could never ever see with the nakes eye, we couldn't even see it with a loop, we had to look at it upsidedown under a microscope........ Just wanted to say a little something, if someone who is very new to diamonds read this it may lead them to be under the impression that even VVS is not good enough when it's nearly as good as you could get.......