What is a good HCA Score?????

[tyke]

Just when I thought I was learning a few things

. What is a good HCA score? I thought it was under 2, and the lower the better. But then I thought I saw a post questioning a .5 as a poor performer. Where lies my confusion? Thanks. Tyke

 

[belle]

hca is a rejection tool...that''s it. you can''t use it to find a ''better'' diamond with a lower score. can''t.

 

[drkewl]

Tyke,
you use the HCA as an initial screener to weed out poorer cut diamonds. Anything under 2 is great (with some like John at WF saying his personal sweetspot is around 1.0 but thats just one opinion). After that, its up to you to use your own eyes or that of an expert along with finding the right color/clarity/size to find the perfect diamond for you. Things like the brililancescope and idealscope are further tools to help find the creme de la creme.


Best of luck!

 

[strmrdr]

Under 2 is good.
There are some shallow/shallow combos that score in the .5-.9 range that work better in pendants then rings.

 

[Garry H (Cut Nut)]

agreed

 

[RockDoc]

How about this folks......


A stone that the HCA says DON''T BUY....

Gets the worst AGS Cut Grade 10

But it looks incredible - gets VS x3 on the B Scope.

and costs about 20-25% less.

Comment?


Rockdoc

 

[Garry H (Cut Nut)]

Do tell?

 

[Garry H (Cut Nut)]

I expect your stone is like this one Roc?

In which case HCA does not say dont buy it. It just does not comment.

https://www.pricescope.com/community/threads/new-discovery-brilliant-ideal-cut-bic.17695/

If so then it is no longer an AGS 10 as they too have caught up.
I could extend HCA to shallower angles than 28 degrees, but until there are a reasonable amount of stones cut there it seems a waste of time.
And they do need to have thicker girdles to overcome durability issues

 

[Garry H (Cut Nut)]

Bump
Roc?

 

[RockDoc]

Hi Gary

This is a sort of specialzed cut. It is being patented by the person who thought of the parameters.

I understand that the patent registration will be issued, but it hasn''t yet. In respect to the patent owner, I sort of have to keep the details under wraps, until I have his permission to publish them

I am supposed to see some additional ones shortly. and I want to see if the same characteristics follow suit. Even then I will have only seen 3 of them, and as you know I don''t want to make a judgment that people will rely on as being totally consistent - when they may vary.

But when I can ethically comment about it I will.

Just have a bit of patience with me...

Bill Rockdoc

 

[Garry H (Cut Nut)]

This is a bit Wierd

1. Only a 57 facet round brilliant (and princess) can get an AGS grading
2. Patents have a publicly declared application for some years before examination. e.g HCA is being examined now after being ''pending'' for some 4 or 5 years. this information is easily and publically available. hRD even list all diamond and gem related patants and new app''s from around the world.
3. So once he has lodged the Application (ie it is pending examination) it is pubilc record because a patent is a licence for a 15- 20 year legal monopoly.
4. he will not be allowed to claim ''paramaters'' of a RBC as an original piece of art (in the Aussie Classic - the Castle "Tell''im ee''s dreemin"

So sounds like BS to me

(if he has told you about it prior to lodging the app - you can go do it commercially and he cant stop you)

 

[RockDoc]

Hi Garry

I guess time will tell. Supposedly in its in the last stages of it.

Bill / Rockdoc

 

[Garry H (Cut Nut)]

Of an application.

One that sounds like he might be wasting a lot of $ if it is parameters / painting / digging etc only and not additional facets.

Keep us informed

 

[Mara]

There are always going to be those stones that the HCA dislikes and the AGS cut grade dislikes but the other reports like etc.

For me personally the HCA is just ONE tool amongst many. My criteria for finding a stone does not include SOLELY relying on the HCA score. I have seen enough stones in person to know what my sweet spot is with things like table/depth/crown and pavilion angles. What to stay away from on girdles. What to look for in diameters. etc. The HCA is just one more thing that helps me separate the wheat from the chaff.

For me personally a stone like what RockDoc is saying, AGS10 with a crappy HCA score but great BS reports, is not really a stone I''d be super interested in buying, even at 20-25% discount...for a RING or something that gets scrutinized daily or hourly in some cases. Possibly for a pendant or something where it wouldn''t be subject to close scrutiny, but part of my diamond nuttiness for things like a ring stone or something would be specs and numbers on the diamond.

So I have a list of requirements that the stone has to meet, including HCA but not limited to it.

That said, Brian at WF has also told me he feels like the sweet spot on the HCA is 1.0. I try to steer clear of the stones that score 0.6 or under for reasons mentioned previously re: lack of scintillation. I also probably wouldn''t buy a stone that has an HCA of 2.5 having been there done that and been disappointed in the end. Also, the HCA does change from time to time, Garry makes changes to it, so a stone that scores 1.5 one day in a month or two could score 2.0 or similar. So don''t rely TOO much on the HCA....I''d use it as one tool combined with others and find your own sweet spot for a comfortable purchase.

Babbling now! Good luck.

 

[strmrdr]

Well said Mara.
The more tools you use the better.
If multiple tools conflict then id just move on there are lots of diamonds out there and wasting time figuring out why one likes it and another doesn''t isn''t worth my time.