crown and pavilion angles

[dolphin]

I''ve been presented with the GIA certs for two different diamonds by two different seller acquaintances. I tried to obtain the crown and pavilion angles but neither seller can tell me ''cuz they are sourcing the diamond from overseas wholesalers. Both sellers seem to be telling me they often trade on diamonds based on the GIA certs (without knowing the crown or pavilion angle information) and that both diamonds are good. Are they able to assess the cut quality based on the certs? Below are the information of the two GIA certs. Could someone please advise me which one is better? Estimated cut quality? Thanks very much!

Diamond 1 (Round Brilliant)
1.54 carat, d color, vs2, 7.49-7.52 x 4.54mm;
table 60%, depth 60.5%, very thin to medium faceted, no culet, good polish, very good symmetry; no fluorescence
comments (pinpoints are not shown)

Diamond 2 (Round Brilliant)
1.59 carat, d color, vs2, 7.38-7.43 x 4.66mm;
table 59%, depth 62.9%, medium to slightly thick faceted, no culet, good polish, very good symmetry; no fluorescence
comments (pinpoints are not shown)

 

[valeria101]

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On 4/28/2004 3:02:51 AM dolphin wrote:




Both sellers seem to be telling me they often trade on diamonds based on the GIA certs (without knowing the crown or pavilion angle information)

... definitely true


and that both diamonds are good.

... just ask what 'good' means. This is not rocket science (and you'd be amazed how clearly even that can be explained to a layman).




Are they able to assess the cut quality based on the certs?

... definitely not in the sense of 'ideal' cut of Harts and Arrows as described by the tutorial here


Below are the information of the two GIA certs. Could someone please advise me which one is better? Estimated cut quality?


No, it would be impossible to precisely evaluate 'cut quality' in terms of predicted light return. Anything is possible with the specs given and the chance that these get close to the optics of the respective optimal proportions (as er HCA and related) are somewhere below half... You might want to inspect the HCA charts for the given table measure - there is allot of room (menaing combinations of crown and pavilion angles possible for the given specs) for error. The sellers could not know more based on the certs, although they could probably pinpoint the respeective probability better. This is why it may be worth going for a stone already in posession of the seller and/or fro which all details are available. If you are looking for top cut quality (as you obviously are fot color and calrity) that is

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Hope this helps....

 

[dolphin]

Thanks Valeria101. I'll try to obtain more info as you suggested. Would you be able to advise based on the cert info, which one seems better? Thanks again!

 

[valeria101]

Proportiosn seem just as good in both, but I am not at all confortable with the "very thin girdle" in the first stone. It could be argued that for some otheewise perfect stone one could find excuses for a small area of the girdle that qualifies for 'very thin' - otherwise, who wants a chipped diamond?

Nothing online seems tempting?

 

[diamondsman]

# 1 is the better stone in this case,The diameter of the stone is bigger,the depth and table are correct,the girdle is more uniformed,evrything is just right on that stone .I would go for # 1 without hesitation.(Asuuming that the price is close)

good luck

 

[bling]

if i had to pick between the 2, i would go with #1 also. #2 is a larger ct weight, but its weight is where you cant see it. if you compare the mm of both stones, you will se that #1 is smaller in ct weight but has a larger mm. it will face up larger. also, #2s thick girdle adds to its visually smaller apprearance. im by no means an expert, but just humble .02! good luck..have you tried looking at some of the vendors here?

 

[dolphin]

Thank you everyone for your advice. You've been very helpful. Indeed the price of both diamonds are very close. I'm starting to favour #1 more now. In the meantime, I'm trying to obtain more info on the quality of the cut. Thanks again.