Critique this rock: Slightly low crown angle - dealbreaker?

[miraj]

I'm looking for a spectacular diamond and this one seems to check all of my boxes:
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3508621.htm

I'd appreciate the PS suggestion for whether to pull the trigger on this one!

My biggest concern is that the crown angle (34.1) is just a bit lower than I have seen recommended (34.3-34.9).

I gave my criteria in an earlier post, since it is a little long to also write here.

Many thanks!

 

[ecf8503]

Re: Critique this rock: Slightly low crown angle - dealbreak

It's an ACA - it's beautiful. No worries.

 

[diamondseeker2006]

Re: Critique this rock: Slightly low crown angle - dealbreak

Only top diamonds get in the Whiteflash ACA category. 34-35.0 is fine for a crown angle in the ideal cut range, so that is not a low crown angle. That is a fabulous diamond and very hard to find just under 2 cts!

 

[miraj]

Re: Critique this rock: Slightly low crown angle - dealbreak

Glad that you guys approve so far... some more things I'd appreciate your opinion on:

Whiteflash marked it as eye-clean - how reliable is Whiteflash's guidance on that?

The center/table facet seems quite large to me. Will that reduce the scintillation effect?

I'd appreciate any help in judging the ASET and Idealscope. I think I see light leakage in the edge's triangles (white in Idealscope and pretty dark green in ASET) and I wonder if that is a significant problem.

 

[tyty333]

Re: Critique this rock: Slightly low crown angle - dealbreak

Looks like a beautiful stone. 58% is the top range we usually recommend on table size. It's under that. It should be
fine. It's also a VS2. That, along with them saying it's eye-clean should be proof. I've never heard of WF declaring something
eye-clean and then a buyer coming back to say it's not. You can certainly ask a gemologist at WF just to double check.

 

[D_]

Re: Critique this rock: Slightly low crown angle - dealbreak

Their definition of eye clean is "No inclusions visible to the naked eye of a person with 20/20 vision when viewing the diamond in the face-up position at a distance of approximately 10 inches under normal overhead lighting ."
Is this the same as your definition of eye clean? (keeping in mind that people can't see it closer than 6" and most people beside yourself and the wearer will normally look at it from 10" or further).
You can check to ask them if it's eye clean from the side/pavilion etc. and they will give you an honest answer.

ASET and IS look great. The dark green areas are where they are supposed to be.

Were you getting the parameters from NiceIce etc?
Usually we look at 34-35 degree of crown angle as being safe here (especially with complimentary pavilion angles).
But I remember reading Todd saying something like 34 degree is already getting iffy.
Sometimes I wonder if regular consumers (or even prosumers) can tell the difference 34 from 34.3, is it really that significant?
Maybe the vets can weigh on this.

 

[miraj]

Re: Critique this rock: Slightly low crown angle - dealbreak

Great idea on requesting eye-clean look from the side/pavillion. Definitely interested to know!

I was getting those parameters from niceice, beyond4cs, diamonds.pro, and maybe some others. I just combined the most stringent recommendations from each of them.

 

[WinkHPD]

Re: Critique this rock: Slightly low crown angle - dealbreak

Great idea on requesting eye-clean look from the side/pavillion. Definitely interested to know!

I was getting those parameters from niceice, beyond4cs, diamonds.pro, and maybe some others. I just combined the most stringent recommendations from each of them.

Diamonds are properly graded from the top. Many ask for a diamond to be perfect from the side, which they can not normally see once the diamond is mounted.

While it is fun to require invisible from all angles, be prepared to spend more money. It would be VERY rare to find a VS2 with eye visible inclusions from the top for a person with normal vision. It would not be all that rare to find them from the side because of the way that a diamond reflects light within the diamond. When you want eye clean from all directions you may need to move to a VS1 or even a VVS2 depending on the diamond and on YOUR eyes.

Wink

 

[kenny]

Re: Critique this rock: Slightly low crown angle - dealbreak

I ignore those charts with ranges of specs because they are misleading
They convey a dangerously inaccurate message ... as long as all the specs are in the stated range you have excellent light performance.
Not necessarily so.
The specs interact.

One spec at one extreme end of the range may be compensated for by another spec being at another extreme ... the net result being the light return is still great.

It's complicated.
That's why the HCA is groovy.
It does the complex math of how the four specs interact.

I'd throw all those spec-range charts in the trash.
The HCA is better and free.

 

[miraj]

Re: Critique this rock: Slightly low crown angle - dealbreak

Two more questions on the ASET and H&A.

The blue portions show a gradient towards more black that other diamonds do not - is that a concern?

The H&A image shows white around the edges - is that light leakage, and worth concern?

In this comparison you see how the blue is solid color (no gradient) and the edges have much less white in the other two stones:
http://www.whiteflash.com/loose-diamonds/compare.aspx?idnos=3568736,3568732,3508621

Thanks!