Originally Posted by West24
yea the rapaport is based out of ny city though and may not be accurate everywhere.
It is widely used by wholesalers and major diamond buyers nationwide, and is definitely used here in Houston.
Originally Posted by Pennglock
There are some smart tradeoffs within the 4-Cs, IMO, for maximizing the diamond you get for the price. For instance, it's possible to find diamonds rated SI1 (some inclusions) where the inclusions are such that they're invisible to the naked eye or else easily hidden by the setting. You need to master the loupe or else have a jeweler you can rely on to pull off buying a SI1, though. It's also my experience that it's very difficult to tell a color difference between a D and F stone.
Cut and Carat are the most important characteristics, provided the diamond in question has no inclusions visible to the naked eye and is relatively colorless. The cut is what really gives a stone it's sparkle... it's the performance of light hitting the stone.
Whatever you do, I'd get an ideal cut stone. Nothing below a GIA rating of "excellent," and even that excellent rating would not be enough for me. Not every excellent rated GIA stone is created equal. There are one or two agencies, I dont remember their names, with a stricter set of cut guidelines than the GIA, and getting a rock with their top rating would be good. A perfectly cut round diamond will show symetical arrow shapes if you're looking at it from the top, and heart shapes if you're looking at it from the bottom. Several boutique jewlers have trademark names for these "hearts and arrows" diamonds. You may want to look into them.
Tiffanys is ok. You're not going to get sold a dud there, and their markup on diamonds is actually pretty reasonable compared to their other jewelry and other brick-and-morter stores. My experience with them was, though, that they were not willing or able to focus on the cut of their diamonds, treating all their cuts in the store as equal and trying to make the sale based on the other Cs. I wanted a perfectly cut diamond and wasn't sure I was going to get it there.
All of the beginning advice is good.
And yes, Tiffany is certainly OK but anyone in the trade will tell you that their quality and markup is almost certain to be at the very highest end.
If you want security, name recognition, and the "Diamond Buying Experience for her", as opposed to an internet or wholesale purchase, then Tiffany can be excellent. But be prepared to pay top dollar.
An affluent friend of mine just bought a nice 3 carat stone from a direct wholesaler for 45K. He then went to Tiffany with another friend who is a very competent gemologist. No 2 stones or GIA certs are exactly the same, but the closest stone that Tiffany had was 72K. That's a big difference. If cost doesn't matter, and the "Tiffany Experience" and provenance are important to you, then by all means I would recommend them. But you are going to pay top dollar.
Originally Posted by audiophilia
Good short answer to your initial question.