I believe the "D" on the inside shank is with newer models (past 5 years-ish).
It's great that you had a chance to look at and compare a variety of diamonds in person! Since you have your CBI, I'm very surprised that didn't sway your gf away from Tiffany. How cool that you got to use your Idealscope/ASET/loupe on all those wares!
I'd also suggest catherine trenton jewellery for checking out second-hand, authenticated Tiffany rings.
For example, this one: https://www.catherinetrentonjewelle...1-legacy-diamond-and-platinum-engagement-ring
0.87 tcw F VVS1 legacy with all paperwork and boxes etc, for under 7k USD.
@chappy, very nice find. Forwarding to GF.
Was only able to use my scopes on the loose HOF and Fire&Ice stones. Unfortunately, C&H didn’t have loose Forevermark. For Cartier and Tiffany, wouldn’t have needed scopes even if were hypothetically loose. When she compared their preset G colored options to my G super ideal, the others exhibited a definite yellow tint when held/worn side by side with mine. At least convinced her that cut is important and can affect “whiteness” of stone besides light performance (although I wonder if the medium blue fluorescence in mine played a factor). If she is not able to find a Tiffany ring that she can fall in love with, I will help her explore the better options. But at the moment, don’t want to complicate, so trying to find that Tiffany cushion cut dream ring.