63.9 total depth is too deep. It drags the cut into 3A AGA grade. Although we don't know exact crown and pavilion angles for your diamond we can try different combinations that together with girdle thickness will give you total depth.

Garry and I have Diamond Calculator that makes it very easy. If you’re using Internet Explorer you also can play with numbers using this tool: http://www.cutstudy.com/cut/Brill/e_ray_thin.htm.

Having fixed total depth 63.9%, 55% table and 3% girdle you can have certain combinations of crown and pavilion angles. E.g.:

Crown angle – Pavilion angle
32.6 - 44.0
33.0 – 43.0
35.5 – 42.0
37.9 - 41.0

None of these combinations as well as anything in between will give you the best result.

could you please check on these numbers.

62% depth
56% table
crown angle 34.8
pavil angle 41.2
culet is 0.9%

Thanks,

Genie

These numbers looks better than for previous one. I guess it is AGS0 graded stone, right? If so you would be asked to pay premium for it. Please be aware that AGS0 range is too broad and not all AGS0 are equal.

41.2 is the most deep pavilion allowed for AGS0, 0.5 degree deeper than Tolkowsky. In combination with 34.8 it causes a partial light leakage under the table. See www.pricescope.com/tutor_agsideal.asp .

Have a look at the light return plot from MSU cut study research, www.cutstudy.com/cut/english/document4_1.htm . You can see how light return drops below 1 (Tolkowsky) at this combination of crown and pavilion angles.

Another example of the deep pavilion effect on the diamond performance you can find at www.goodoldgold.com.

This AGS0, www.goodoldgold.com/148.htm,
has 56% table, 34.7° crown and 40.5° pavilion angles. It has very high readings on Brilliancescope and rated Excellent on HCA.

Another one (almost like your stone above), www.goodoldgold.com/newpage35.htm , 55% table, 34.8° crown and 41.1° pavilion angles, has much lower Brilliancescope reading and HCA score only Very Good.

you were right. Could you check on one more please? here are the specs

depth 61.5%
crown angle 34.0
pavil angle 40.9
table 56%
culet 0.9%

thanks,

In this case a bit deeper than Tolkowsky pavilion angle is compensated by a shallower crown.

The last diamond should be very nice. Although if you want more perfection you can look at "super ideal" branded Hearts and Arrows diamonds like A Cut Above ( www.whiteflash.com ), Superb Cert ( www.superbcert.com ), Aglaia, Hearts on Fire ( www.heartsonfire.com ).

Next level would be EightStar diamonds, www.eightstar.com .

It is always a good idea to see many different diamonds. You can try to find knowledgeable dealer who carries different brands and decide yourself what make you want.

Lawmax followed the same way, I think, and ended up with EightStar

However, even if you'll decide to go with any brand name diamond, don't forget to check them by the Cut Adviser as well.

The stone above:
Heart and arrow
crown angle: 34.2
pavillion angle:40.9
table: 55%
total depth: 61.5%
D color
VS2

Or this one:
A CUt above heart and arrow
crown an:34.7
pavil an: 40.8
table:53%
total depth: 61.9
E color
VS2

A few tenths difference in the HCA score should not be a decisive factor. There are others. Since both stones are H&A you have to make sure whether H&A pattern is prefect. A Cut Above diamonds are known for its consistency. You have to use H&A viewer to see whether H&A images are perfect (see http://www.pricescope.com/hearts_grading_hearts.asp).

The first one has D color while the second one E. You have to weight all these factors plus price.

One more small note. Because of proportions the first diamond can be a bit more brilliant but less fiery than the second one.

[This message has been edited by leonid (edited 02-22-2001).]

When I said the first one is a bit more brilliant while second one has a bit more dispersion (fire) it is only in theory and the difference can be very slight. One has to eyeball both them to tell.

I agree with Whiteflash - if you are going to pay premium for H&A, you might what to make sure that the diamond is a true H&A.

On the other hand, although you won't see the difference between D and E, there is a difference in the market price.

Darn! Tough situation!

Could you get H&A images for both diamonds? What is more important for you: superior cut or the color difference?

It's tough when you can't compare the two diamonds. You could have them both sent to an independent appraiser (many dealers will send stones to Dave Atlas www.gemappraisers.com or Bill Lieberum www.consumersgemlab.com (he's out of the country right now) before the consumer actually pays for the diamond. Then you pay the appraiser's fee for examining both diamonds.

Personally, I would not pay for the "c grade" hearts and arrows pattern. I would go for the best possible symmetry.

Also, I think the magic of extremely well-cut diamonds is the fire they produce, especially in dim lighting. It is easier to produce diamonds that are brilliant than it is to produce highly dispersive diamonds. The rainbow flashes can be awesome. I realize the difference here may be minimal, none, or something else.

It is hard to tell you which diamond you would like better-I'm sure they are both very beautiful. I think a 53% table is quite small.

I would doubt that you would see the difference betweeen the D and E colors, especially after they are mounted.

Hope this helps,

lawmax

[This message has been edited by lawmax (edited 02-22-2001).]

Table 55%
Depth 61.6%
Crown angle: 34.4
Pav angle: 40.7
Pav % 42.6
E
VS2
A Cut Above heart and arrow

This one was a little better in price, maybe because it is a smidge lighter (.72)? What do you all think of this one?