Find your diamond
Find your jewelry
shape
carat
color
clarity

Does low HCA score means a good diamomd?

Diamondfresh

Rough_Rock
Joined
Apr 8, 2019
Messages
20
20190516_160641.jpg I am interested in this diamond but the HCA score is around 5. Price is approx USD 8,500. Does high HCA score means the diamond is not as good?
Screenshot_20190516-162429_Gallery.jpg
 

Sponsored By:

kmoro

Brilliant_Rock
Joined
Sep 13, 2018
Messages
1,076
Diamonds are cut so that the facets act like mirrors ... there are certain angles that these mirrors need to be in order to reflect light in an optimal way. The HCA gives an indication of how well the angles of your diamond can be expected to work together. With GIA, there is rounding of numbers, so the HCA can not always be accurate ... it is a rejection tool only ... it can not be used to choose a diamond but is quite effective in weeding out definite poor performers. If you have a diamond that scores 5, it should be rejected as you can find much better.

Here is a super-ideal A Cut Above 1.071 ct G eye-clean VS2 around the same price .... it is gorgeous with a very small table that is highly sought after by those who love diamond fire ... you would be with a top-notch vendor and a $1 upgrade policy ... imo, this would be a much better option. This is AGS graded, meaning it has been evaluated for light performance, no rounded numbers, no guess work or HCA required, and has the top score.

https://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3999639.htm
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
4,075
Although the overall depth for this stone is within acceptable criteria, the bigger issue is it's "pavilion heavy".

The pavilion is 41.6, resulting in 44.5% pavilion thickness. At 41.2+ angle things go really wonky. So even if the other properties are great this isn't a good performer.

Even if you were chasing a 60/60 stone with 33/41 combo, you'd want to make sure the actual values didn't cross that 41.2 threshold.

While HCA doesn't always guarantee a winner, in this case its score is indicating an issue and you'd be wise to listen.

I would pass on the stone in question.
 

diamondseeker2006

Super_Ideal_Rock
Premium
Joined
Jan 11, 2006
Messages
55,220
Look for GIA Ex cut stones within these parameters:

Table 54-57
Depth 62-62.3
Crown angle 34-35.0
Pavilion angle 40.6-40.9
 

TimMD

Shiny_Rock
Joined
Jan 19, 2011
Messages
252
I agree with the others, I think there are better stones to be found.

@diamondseeker2006 Do not want to thread jack but since coming back around a few months ago, I have been meaning to say hello, glad to see a familiar face after all these years and I always appreciated your sound advice and friendly comments =)2
 

OoohShiny

Ideal_Rock
Premium
Joined
Apr 25, 2014
Messages
6,636
Look for GIA Ex cut stones within these parameters:

Table 54-57
Depth 62-62.3
Crown angle 34-35.0
Pavilion angle 40.6-40.9
That seems a more restrictive set of parameters than I've been using/recommending - I've been suggesting these!

T 54-58%
D 60-62.4%
P 40.6-40.9 degrees
C 34-35 degrees (up to 35.5 with 40.6 crown angle)
 
Be a part of the community It's free, join today!

Need Something Special?

Get a quote from multiple trusted and vetted jewelers.

Holloway Cut Advisor



Diamond Eye Candy

Click to view full-size image.
Top