Need Opinion

[gone2seeu]

Need some opinions on this stone I looked at it yesterday and it seems to have good fire for a oval. Please let me know what you on the forum think.
Thank you

SI1 F color
1.075
Width/Length 5.63 - 7.49 L/W Ratio 1.331
Total Depth % 68.6 3.86 mm
Crown Angle 34.3
Crown Height 13.5%
Pavil Angle 43.7
Pavil Depth 46.7%
Table Size 61.0%
Girdle Thickness 8.4%

 

[gone2seeu]

If I left something off that someone needs to give me an opinion on the cut of this oval diamond please let me know surely somone on this site knows about oval cuts cause I don't.

 

[valeria101]

You might want to check "Fancy Cuts" chapter of the cut quality tutorial here - it makes a good explanation on why certain cut proportions are deemed more desirable than others. Some of the respective body of knowledge is nicely resumed into a table of cut proportions (LINK). The site where it is comming from is by all means worth inpsecting too.

Otherwise, there is no hard and fast rule to determine wether an oval has achieved best possible brilliance, based on only a few easy-to-get numbers. Instead, the stones can be ranked for how much brilliance they deliver using devices such as the Ideal Scope (explained at Ideal-scope.com) and the Brilliance Scope... Both give some good prediction of what stones look like 9if you haven't seen them, buying online) and, in any case, wouldprovide a 'grade' for the stone, by comparing it's optics with the best achievable for the cut. For a quick example of how such things work, you might want to take a look at THIS example

Of course, nothing bad about the stone you describe: I'd had it less deep, but otherwise why not? Not sure what to make of the 8% girdle - that's so much I believe it to be a typo...


It makes some sense, I guess, to know what else is out there. And this is why I listed all these.

 

[valeria101]

Oups! I wanted to mention the "Virtual Model" on the "example" webpage...

 

[gone2seeu]

Valeria, Thanks for the info I printed the aga rules. As far as the gridle thickness I took this information from Gem X report itit show 8.4% (8.1-8. for what ever it's worth. I notice that the aga rules go by thickness is there anyway for me to convert the 8.4 over to the aga rules
Thanks

 

[Giangi]

8.4% translates to extremely thick. I think you are loosing quite a bit of weight in the girdle and a stone with a medium or slightly thick girdle would face up slightly larger. Basically you are paying for some weight you can't see that's hidden in the bottom.

 

[gone2seeu]

Thanks for the input Giangi. I'm getting a more than fair price on the stone I think at 3000 per carat but I'm concered about the light return with the girdle thickness. It appears really brilliant under the lights then outside in the sun it looses some of it's luster. The person receiving doesn't want anything real fancy although I'm trying to put togheter something fancy I have all the stones picked but the center.

 

[valeria101]

As a side note... one can find very nicely priced 1carat stones out there which, for one reason or another do not 'look' like their average brother of same weight - these are discounted for the detraction caused by the cut, and even sellers would tell you that such stones appeal for whoever selects stones by weight instead of size. Not great

BTW, as a measure of the respective discount.... the price per carat for 1 carat F-SI ovals runs from 3300 upwards here for GIA certified stones and goes to 2900 for some that got their blessing from EGL.

Hoever, it would be depth and proportions dictating the exact size, not weight alone within ten points or so. The 10% discount accounts for this 10% weight burried in the cut, I suppose.

 

[valeria101]

Case in point...

0.91 F-SI1 with the same face up size as yours (I took area for this) and $3071 on PS listing.

After some search, it appears that a thin-medium girdle for an oval is by no means the rule! Only very few reports read anything but "Thick" and/or "Very Thick". However, I would look at THIS one - the size and proportions look very promissing.

Looking for these I just took into account the price and size you mention and some reasonable boundaries on cut proportions.

Hope this helps.