DIY 2A, HCA 5 weird?

[sunnyinstl]

I am looking at a stone that has these two proportions. is that weird. seems that DIY 2A is a quality cut stone, but a 5 on the HCA is terrible. any help. the stone looks good when i saw it in person, great brilliance, good fire.

 

[valeria101]

What are those numbers ??

 

[sunnyinstl]

Measurements 7.72 X 7.68 X 4.86
Depth 63.1
Table 58
Crown 15%
Pavillion 44%
Girdle Medium, Faceted
Polish G
Sym VG
Cutlet None

 

[valeria101]

Yeah...

it seems that the DIY firt two grades (if not just 1A) agree with the HCA "top grade" (=score <2). Beyond that there''s little left to say.

As far as I know these two rating systems track slightly different things: the HCA tries to guess brilliance and the DIY is supposed to give a holistic view of sorts (the factors taken into account are not listed... so I don''t know for sure how they relate other quality aspects but brilliance to those numbers).

The HCA goal is allot more demanding so the scores are stricter...

Have you got a chance to compare this stone with an ideal cut one ? All diamonds are nice taken separately. With just one diamond at hand. it''s taugh to guess if allot better is feasible or not.

Any chance to give that HCA score a reality check using the Ideal Scope or something ? It would be easier to tell what is going on with this stone in particular based on a standard view of it''s looks rather than the couple'' numbers there.

Just a thought, as usual

 

[oldminer]

In the AGA system, the stone is simply slightly too deep to be noted as "finely crafted", cut class 1.
It becomes 2A.

The HCA tries to adjust for light return which may be decent in such a stone, or might also not be very good. In my newest DFS cut grade strategy to be used with ImaGem light measurement, the stone still would be downgraded for cut due to the depth....Some things won''t change. However, via ImaGem, the light behavior would not be a guessing game any longer. We''ll provide direct measured numbers.