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what if crown angle is >35

metsfan2016

Rough_Rock
Joined
Jan 21, 2016
Messages
13
Hi all. So I have been doing a lot of research and reading here on pricescope and I have come to learn that preferred specs are:

table 54-58
depth 60-62.3
crown angle 34-35
pavilion angle 40.6-40.9

But my ultimate question is, what if a diamond is cut outside of these specs? Does that make it a poor diamond? I'm asking as I came across a 1.3c diamond with the following specs:

table 57
depth 62.3
crown angle 35.60
pavilion angle 40.6

Based on what I have read the crown angle is larger than recommended but what does that really mean? Will I notice anything "off" when I look at it?
 

diamondseeker2006

Super_Ideal_Rock
Premium
Joined
Jan 11, 2006
Messages
55,757
It means there could be leakage which would diminish light return. But sometimes that amount of difference is okay...those you absolutely have to have an idealscope or ASET Image to see if there is leakage.
 

flyingpig

Ideal_Rock
Premium
Joined
Nov 7, 2015
Messages
2,267
metsfan2016|1453399550|3979185 said:
table 57
depth 62.3
crown angle 35.60
pavilion angle 40.6

Based on what I have read the crown angle is larger than recommended but what does that really mean? Will I notice anything "off" when I look at it?
40.6/35.6 can be good.
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3569940.htm

As DS said, there is no way to confirm without ASET.

Out of curiosity, is it graded by AGS or something else?? GIA reports the crown angle in the multiple of 0.5 only
 

metsfan2016

Rough_Rock
Joined
Jan 21, 2016
Messages
13
diamondseeker2006|1453399780|3979192 said:
It means there could be leakage which would diminish light return. But sometimes that amount of difference is okay...those you absolutely have to have an idealscope or ASET Image to see if there is leakage.
I've attached the diamond information below....it includes an ASET. don't see any excessive light leakage (I'm new to this so I may be wrong) but I am seeing less intense light, especially on the right hand side. I'm not sure how this will effect the look of the diamond. Will it look dimmer on the edge and make it appear smaller? Is this a bad ASET ??

http://www.goodoldgold.com/ecommerce/1.3ct-h-vs2-platinum-select-round-ideal-cut-diamond.html#
 

metsfan2016

Rough_Rock
Joined
Jan 21, 2016
Messages
13
flyingpig|1453400429|3979205 said:
metsfan2016|1453399550|3979185 said:
table 57
depth 62.3
crown angle 35.60
pavilion angle 40.6

Based on what I have read the crown angle is larger than recommended but what does that really mean? Will I notice anything "off" when I look at it?
40.6/35.6 can be good.
http://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3569940.htm

As DS said, there is no way to confirm without ASET.

Out of curiosity, is it graded by AGS or something else?? GIA reports the crown angle in the multiple of 0.5 only
It is GIA graded, I took the specs from the SARIN report which wasn't rounded up.
 

ssgg

Rough_Rock
Joined
Dec 25, 2015
Messages
28
if it isn't the usual "ideal" angles.

you can always use HCA to check if the angles complement each other.
according to your average measurement.
table 57
depth 62.3
crown angle 35.60
pavilion angle 40.6


HCA
Light Return - Excellent
Fire - Excellent
Scintillation - Excellent
Spread or diameter for weight - Very Good
Total Visual Performance 1.5 - Excellent
within FIC range

However, if average angle is 35.5 as in the gia report. It would be

Total Visual Performance 1.5 - Excellent
within TIC range




Personally, if I have a gia 3ex stone, I will cross reference it with the ags charts to see if it might fall in the AGS ideal category.
 

diamondseeker2006

Super_Ideal_Rock
Premium
Joined
Jan 11, 2006
Messages
55,757
ssgg|1453437770|3979539 said:
if it isn't the usual "ideal" angles.

you can always use HCA to check if the angles complement each other.
according to your average measurement.
table 57
depth 62.3
crown angle 35.60
pavilion angle 40.6


HCA
Light Return - Excellent
Fire - Excellent
Scintillation - Excellent
Spread or diameter for weight - Very Good
Total Visual Performance 1.5 - Excellent
within FIC range

However, if average angle is 35.5 as in the gia report. It would be

Total Visual Performance 1.5 - Excellent
within TIC range


Personally, if I have a gia 3ex stone, I will cross reference it with the ags charts to see if it might fall in the AGS ideal category.
You don't have to do that if you use the HCA. There is a diagram on the page that plots the stone according to it's measurements, and AGS Ideal cut area will be shown by the solid white outline. You can see if the X falls in that area or not.
 

ssgg

Rough_Rock
Joined
Dec 25, 2015
Messages
28
I don't think the hca is showing the ags labs latest chart (2008)

I have a diamond that isn't within or the white outline on HCA plot. But it is according to the AGSLproportions chart (2008)
 
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