how much do you lose w/ deep depth?

[vslover]

Just curious...in a small diamond with a 63% depth, how much size are you really losing? Any formula to figure it out?

 

[oldminer]

to estimate the approximate weight of a round diamond with a medium girdle thickness multiply maximum diameter x minimum diameter x depth x .0061.

If you have a diamond with a 63% depth, recalculate the depth to 60% or whatever other depth you want to test and re-do the calculatin with the lower depth measure using the supplied formula. You will see how much less the same diameter diamond would weigh with the shallower depth. The extra weight of the deeper diamond is sometimes beneficial to beauty and often simply like untrimmed fat on a steak. It can be a combination of benefit and detriment, too.

 

[Garry H (Cut Nut)]

Date: 3/15/2008 5:40:02 PM
Author: oldminer
to estimate the approximate weight of a round diamond with a medium girdle thickness multiply maximum diameter x minimum diameter x depth x .0061.

If you have a diamond with a 63% depth, recalculate the depth to 60% or whatever other depth you want to test and re-do the calculatin with the lower depth measure using the supplied formula. You will see how much less the same diameter diamond would weigh with the shallower depth. The extra weight of the deeper diamond is sometimes beneficial to beauty and often simply like untrimmed fat on a steak. It can be a combination of benefit and detriment, too.

these 2 stones are CZ eqivalents of 1ct each, one is 6.25x4.3mm and one is 6.5x4.1mm.
The size difference is more because of the diference in light return near the edges

 

[strmrdr]

a formula will tell you what you lose in actually spread what you lose in performance as Garry shows is a whole nuther story.
Most RB on the market 63% and over are dogs but if cut right a 63% or even 65% depth round can be a smokin diamond.

 

[WinkHPD]

I have never seen a 65% deep round brilliant that was not a dog. I suppose it is possible, but I don''t think it would be very common.

Wink

 

[Ellen]

Date: 3/15/2008 11:23:41 PM
Author: strmrdr
a formula will tell you what you lose in actually spread what you lose in performance as Garry shows is a whole nuther story.
Most RB on the market 63% and over are dogs but if cut right a 63% or even 65% depth round can be a smokin diamond.

I''m assuming none of those would be GIA Ex''s you''re referring to. Otherwise, I hope youknowwho doesn''t see this.

 

[elle_chris]

Speaking of depths, I was in Zales a few weeks before I purchased my stone.
When I looked at their rings and asked about the measurements, they were all small for their size and the average depth there was 65. In those lights though, boy oh boy did they sparkle.
I can totally see how people get taken by them if they don''t know the standard size for carat weight. OH, and they had a 2ct that was way under 8mm, H, SI1,
graded by IGI, for 20k. They also had a 3ct 8.50mm stone, H, I1 for 32k. I was shocked.

 

[Lord Summerisle]

Date: 3/16/2008 10:11:35 AM
Author: Ellen

Date: 3/15/2008 11:23:41 PM

Author: strmrdr

a formula will tell you what you lose in actually spread what you lose in performance as Garry shows is a whole nuther story.

Most RB on the market 63% and over are dogs but if cut right a 63% or even 65% depth round can be a smokin diamond.

I''m assuming none of those would be GIA Ex''s you''re referring to. Otherwise, I hope youknowwho doesn''t see this.

and que another 15 page thread...

 

[strmrdr]

Date: 3/16/2008 9:17:36 AM
Author: Wink
I have never seen a 65% deep round brilliant that was not a dog. I suppose it is possible, but I don't think it would be very common.

Wink

Who said anything bout rounds being limited too RB's :}

That said the deepest RB iv seen that was smoking was 64.7 and it was almost all in the crown.
rare bird indeed.
It was likely cut from a cap and a large inclusion had too be cut out.
64.7 AGS1 potential.
36/40.6/52T/80lgf/2.6 girdle. 64.7 depth.

edit: I don't know if this is the exact combo I saw all the data it had was table 52 depth 64.7 but it did have nice arrows and was sparky.
.57ct G or H vs clarity... I didn't pay that much attention too it other than cut.

 

[strmrdr]

btw it is no surprise too me that Wink has never seen a nice looking RB in that depth range.
I'm betting several vendors will tell you the same.
They are rare birds and the Jeweler that was selling it was clear it was out of the range he normally looks at but when he was on a buying trip someone showed it too him and it was unusual so he bought it.

edit: I did play with it in several lighting conditions other than the lights over the counter.
Be carefull too do that if you come accross one like it :}