I would probably pick a lighter color. A lighter stone should have more sparkle and fire than more saturated one. I've seen a few stones from Chattham - I liked a lighter one (sky blue?). However, I must admit stones were cut poorly.
As for Adia colors EGL uses this system for color grading (from Adia site - adia diamond/magnificent/color/blue)which is more compex than icestore suggests.
At Adia a lighter stone comes at price. Fancy blue cost much more than similar intense blue. Intense blue cost more than vivid blue and so on. Quite opposite for natural blues!
Myself I'm looking for 3/4ct VS light blue which they don't have at the moment. However, they told me that there are several 70-80 pointers in grading now. Also, they just finished a few stones above 1 ct. For what it worth, Juliegirl.

Adia's blue diamond color chart is nice and probably a better representation of the different color values


Actually, I think Adia's pricing is all based on clarity for some reason -- in naturals it is all about the color! What I really wish is that they wouldn't sacrifice the cut just to get the carat weight they want....

So, Less liked the first one (Fancy Vivid) due to the color and table size. He said the problem with a lot of the blues he has been getting is the large table size which just sucks the life out of a stone.

I emailed Adia and they like #2 (Fancy Blue) because it is the "most pleasing to the eye". I wonder if it is also because it is the most expensive one too? I am going to give Pearlman's a call sometime this week and see what they think too.

Lyta, I was playing with Adia site for quite some time. Needless to say - it's nicely done. Nevertheless, I'd like to make two points. First, pricing. As far as I could do comparative analysis, Adia's prices for blues are based on both color saturation (lighter - more expensive) and clarity grade, and, to lesser extent, on size.
Secondly, cut. Adia's site says that every stone is cut in Antwerpen which in a diamond world stands for Quality (at the expense of cost). Anyway, being a curious girl I went to EGL's site http://www.eglusa.com/egl/servlet/ShowCertificateServlet) and verified Adia's certificate numbers for the stones you've picked. EGL gives more info on cut than Adia. Then with values for depth, table, crown and pavillion I went to Pricescope for diamond cut analysis ( http://www.pricescope.com/cutadviser.asp ). The results are as follows:
#1. Total Visual Performance 3.6 - Very Good - Worth buying if the price is right
#2. Total Visual Performance 1.9 - Excellent
within TIC range
#3. Total Visual Performance 2.4 - Very Good - Worth buying if the price is right.

It means that out of those three stones, #2 is the "best" and #1 is the "worst" (Sorry, Less)

I also liked "if the price is right" - the difference b/w #2 and #3 is 68%!!!!

I suggest you do this exercise yourself for I can't post all info (light retun, fire, etc.) here.

For what it worth,
Julie

Cool, you have obviously spent a lot of time there. It just seemed weird how the pricing was handled. Those are some really neat tools too and I haven't been much of a diamond shopper so I will check them out. I admit I don't know much about table and depth % ....

Anyway, #2 is now sold so I either wait a few more weeks for more blues or I try #1.

Lyta, I could see some rationale behind Adia's pricing model. Natural vivid blue diamonds are more rare that fancy or light blue ones, hence they (vivid) are more expensive. It's not that they sparkle more - no, quite opposite - a darker stone sparkles less.
With synthetic diamonds more beauty (sparkle, fire, scintillation) you could find with a light blue stone rather than with a vivid one. Remove rarity of a vivid blue - who will need a sapphire-looking stone at such a price?

Julie

Well, it looks like I might just wait and see what is in their new batch since the only other stone that measured well on that pricescope tool (1.1) was this one but there isn't a photo!

Price: $2,754 ($5,100 per Carat)
SKU: ABB0164
Shape: Round
Weight: 0.54 carat
Color: Fancy Blue
Clarity: SI2
Certification: EGL # 91147314D
Dimensions: 5.47x5.41x2.60mm
Depth: 47.7%
Table: 69.0%
Polish: Good
Symmetry: Good
Girdle: Thin To Medium
Culet: None
Fluorescence: None

I do think the highest grade I will go is Fancy Intense but I may consider a Fancy Blue too. I do like the less saturated stones but I don't want something too washed out either. Ack, why does this have to be so hard???

Anyway, the setting will be on its way to me soon so be on the lookout for photos!

I LOVE this thread! Thanks for all the research and 'splainin' the rationale, gals!

A lighter blue stone appeals to me much more than the darker blue. As juliegirl says, why pay so much for what might look a lot like a sapphire at a quick glance? No offense to the sapphire lovers (myself included)!

I'm on pins n' needles waiting to see what you choose, Lyta.

Being overall excited about Adia's diamonds I still have a question for you, Lyta. Have you got an answer on their return policy and/or 3% restocking fee? I'm curious because I'm in line to get a light blue 70 pointer. I hate to make a decision (part with money) not seeing it.
On a different note, spending good chunk of time at Adia site - love their 1+ ct asschers! Photos, at least.
Also, fascinated with Kretchmer's Helix ring at Adia/Gallery. Quite a bold statement!

I haven't gotten an answer yet on the return policy but I expect they are taking some time off for the holiday now. Right now I am asking for some photos of the last one I posted above but I am also going to wait until their next batch of blues before deciding what to do. I am totally with you on being so hesitant about buying something without a photo at least.