when is a crown too shallow

[nyclooking]

hi guys -- quick question -- I think I''ve found the perfect stone -- 60.7% depth, 56% table, scored a 1.2 on the HCA. The only thing that''s giving me pause is the crown angle -- it''s at 32.8, which seems low compared to the "ideal cut" proportions that''s been listed elsewhere. I forgot what the pavillion angle was, but I assume it was complimentary since the HCA score is so good. Should I pull the trigger or is that crown angle a concern?

 

[niceice]

The crown angle is a bit shallow for our preference, well honestly more than a bit, but what's the pavilion angle? Please post the full measurements for the diamond, half the information only paints half of a mental picture

 

[nyclooking]

so. true. here's the full spec:

2.08 carat
8.28-8.32 X 5.04
medium girdle
Crown Angle 32.8 degrees
Pavillion Angle 41.1 degrees
Depth 60.7%
Table 56%

what do y'all think? By the way, what's the visual effect of a crown that's too shallow?

 

[niceice]

The fact that the pavilion angle is a little steep usually compensates for the fact that the crown angle is a bit shallow... The stone is probably quite brilliant (reflected white light) and pretty, but not as dispersive (reflected colored light / fire) as it would be if the crown and pavilion angles were more in-balance, for instance, if the crown angle were between 34.3 - 34.8 degrees and the pavilion angle was between 40.5 - 40.9 degrees. Some people prefer a diamond with more brilliance, some people prefer a diamond with more fire, others like us prefer more of a balance between the two factors.

 

[niceice]

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On 3/11/2004 10:55:57 AM nyclooking wrote:

hi guys -- quick question -- The only thing that's giving me pause is the crown angle -- it's at 32.8, which seems low compared to the 'ideal cut' proportions that's been listed elsewhere.----------------

By the way, we should mention that a diamond with a crown angle of 32.8 degrees can not be "ideal cut" because the lowest measurement possible for crown angle on an ideal cut diamond is 33.7 degrees. A crown angle of 32.8 degrees is at the very low end of the range for the range of measurement allowed for the crown angle within the proportions range of 1-Excellent which is between 32.8 - 33.6 degrees. If the crown angle measurement dropped another tenth of a degree, which clearly it does since the measurement listed is based upon an average of the crown angle measurements, then it would have a proportions rating of AGS-2 Very Good at best assuming that all of the other factors remained within the range of AGS-2 Very Good or higher... But this is not to say that the diamond you are considering will not be beautiful because the pavilion angle is the primary reflective surface within the diamond.

 

[nyclooking]

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On 3/11/2004 12:14:30 PM niceice wrote:

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On 3/11/2004 10:55:57 AM nyclooking wrote:

hi guys -- quick question -- The only thing that's giving me pause is the crown angle -- it's at 32.8, which seems low compared to the 'ideal cut' proportions that's been listed elsewhere.----------------

By the way, we should mention that a diamond with a crown angle of 32.8 degrees can not be 'ideal cut' because the lowest measurement possible for crown angle on an ideal cut diamond is 33.7 degrees. A crown angle of 32.8 degrees is at the very low end of the range for the range of measurement allowed for the crown angle within the proportions range of 1-Excellent which is between 32.8 - 33.6 degrees. If the crown angle measurement dropped another tenth of a degree, which clearly it does since the measurement listed is based upon an average of the crown angle measurements, then it would have a proportions rating of AGS-2 Very Good at best assuming that all of the other factors remained within the range of AGS-2 Very Good or higher... But this is not to say that the diamond you are considering will not be beautiful because the pavilion angle is the primary reflective surface within the diamond.
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thanks -- when I loooked at it I thought it was more brilliant and sparkly than anything else I've seen, so it definitely is beautiful. I guess at the end of the day that's what matters more than anything else . . .

 

[Mara]

That could be a really stunning diamond...mine has a 29.9 crown angle, shallow eh?!

It's very white brilliant and sparkly...but that is typical of the more shallower crown angled stones. My pav angle is 41.1 as well. If it looks beautiful, sparkly from all angles, no darkness under the table, you may have found something really great.

See if someone can DiamCalc the stone for you to give you an idea of where light leakage may be on the stone. Garry, Leo? Anyone?

 

[nyclooking]

oh, a diamcalc would be great! thanks in advance. also, as I was thinking about it, it shows up excellent on brilliant, fire and scintillation -- so does that mean the fire isn't compromised? or are there different degrees of excellent? you guys are great. simply great.

 

[Mara]

If the HCA gives it EX on those 3 and VG on spread (I'm assuming anyway)...then the HCA corroborates what your eye is seeing. In terms of being 'compromised' on fire...it's so subtle you may not even notice it. My stone is so much more shallow that I DO notice it doesn't have as much fire, but yours may not be as 'all or nothing' as mine.

Mine does not get EX on the HCA in fire etc. It gets mostly VG's.