20 replies to this topic

[berrysweet050777]

Hi

Need expert advice if this round brilliant diamond is of an ideal or near ideal cut diamond? Looking for somthing of brilliance & fire.

Carat: 1.01
Color: G
Clarity: SI1
Cut Grade: Very Good
Measurement: 6.45-6.48x4.03mm
Polish: Excellent
Symmetry: Very good
Florescene: None
Table size: 53%
total depth: 62.2%
crown height: 14.5%
pavilion depth: 44.5%
pavilion angle: 41.6%
girdle thickness: thin-slightly thick(faceted) 3%
Culet: none

Any info that I missed out pls advice. Thanks all!

[davidelevi]

It depends on who defines the word "ideal". The only precisely documented definition that I know of is AGS's that uses the word "ideal" to define the best cut grade it awards stones using precise proportion and angle data. Based on that definition and on the info above, no it is not an "AGS-ideal" stone.

Some vendors will define "ideal cut" their grandma's glasses. Based on which definition it is much much better than ideal.

So, perhaps, after all, GIA's assessment (or at least, I assume it's a GIA grade) of "Very Good" is not that unfair.

Why did you land on this particular one?

[berrysweet050777]

Ya this is a GIA cert. Thought it looks quite brilliant but I was abit apprehensive on the SI1 clarity. Is the proportion good ?
Will SI1 diamonds in the long run lose its brilliance ? Thank you for any feedback given!!

[davidelevi]

berrysweet050777, on 16 February 2011 - 03:11 AM, said:

Ya this is a GIA cert. Thought it looks quite brilliant but I was abit apprehensive on the SI1 clarity. Is the proportion good ?

See my post above. It's not bad, but it's not the best. Given a fairly steep pavillion and small table, I suspect it may look rather dark, but you need to see it. It sounds like you did, and liked it.

Quote

Will SI1 diamonds in the long run lose its brilliance ? Thank you for any feedback given!!

Only if you don't clean it. Diamond is very stable; clarity will not get worse over time (as long as it doesn't get knocked about and chipped), and it does not cloud over like CZ may do.

[berrysweet050777]

In the jewelley shop under those LED lights all diamonds look shiny so I use paper to hide the lights & it looks ok . And it looks fairly larger than its carat weight...Just that the GIA cert shows the feathers and cloud in the diamond so abit wary of the brilliance in the long run. Based on the specs given, is this diamond about 90% close to a perfect/ideal cut?

[davidelevi]

Brilliance will not be affected by anything other than dirt or severe chipping. You should not worry about that. Dirt you can clean, and chipping you can avoid with a bit of care.

"90$% close to ideal" is a difficult thing to answer - to start with, there is no single "ideal" standard that one can measure from, and personal taste enters the equation pretty quickly. My honest impression is you can do better on cut, but if you like it and the price is right for you, go for it.

[berrysweet050777]

Will a diamond still shine under darkness ? Before that I saw another diamond of D color , VS2 and also 1 carat but it does not shine as much. Why is that so?

[davidelevi]

A diamond reflects light - does not generate it. In darkness, no diamond will shine. In low lighting, some diamonds look great and others can be a bit lifeless; it depends on the way they are cut, rather than their colour.

[berrysweet050777]

So if the cut grade is "very good" in GIA standard then if the proportion of the diamond is excellent it will help in accelerating the fire & shine of a diamond ? Is proportion the equivalent of the measurement of the diamond as specified in the GIA ? In the GIA certificate, it states "Polish" as excellent. What does polish means ? Thank you for all your valuable opinions & insights to my questions!!

[LaurieH]

You keep making comments about "will it lose brilliance in the long run" in regards to the Clarity being an SI1--it's graded based on it's face up appearance under 10x magnification, which means that it could be totally eye-clean, depending on the the type/color and location of the inclusions. However, with the exception of maybe a feather getting struck badly and chipping out further, inclusions don't get worse over time. So as long as the diamond isn't in a position to take on actual damage (and I'd be hard pressed to think of what kind of regular wear situation would make that happen), and the diamond is kept clean, nothing is going ot make the diamond look worse over time. Nothing interior of the stone is ever going to change. I'd say if the stone looks pretty in person and you're happy with it, that's what matters. you're good on Cut Grade, Polish and Symmetry (I always say VG or better on all 3, you're totally fine, and should have really nice sparkle and fire) and if it's a good looking SI1, then I'd say there's nothing else really to worry about with the stone if you like it. As long as you're getting a fair price, I don't see a problem.

Good luck and let us know how things go

[davidelevi]

Cut = proportions. Same thing, in the context we are discussing. GIA awards its cut grade by looking at the proportions of the diamond and how they interact with each other.

Polish is the quality of the finish of the diamond facets, indicating how smooth and free of imperfection the facets are. It will impact the optics, but to a minor extent, and you'd have a hard time differentiating Excellent from Very Good or even Good.

[denverappraiser]

The GIA and AGS cut grading scales also factor in polish and symmetry. A gia 'excellent' must be at least 'very good' on each of those and an AGS 'ideal must be 'ideal' on both. I agree that, visually, VG is just fine for nearly everyone. There may be an argument for buying a 'triple excellent' and paying a slight premium to get it simply because that's top of the scale and that's the scale that's easiest to peg without spending a fortune (unlike color and clarity), but this is a mental thing, not a gemological one.

[jan]

berrysweet050777, on 15 February 2011 - 06:16 AM, said:

Hi

Need expert advice if this round brilliant diamond is of an ideal or near ideal cut diamond? Looking for somthing of brilliance & fire.

Carat: 1.01
Color: G
Clarity: SI1
Cut Grade: Very Good
Measurement: 6.45-6.48x4.03mm
Polish: Excellent
Symmetry: Very good
Florescene: None
Table size: 53%
total depth: 62.2%
crown height: 14.5%
pavilion depth: 44.5%
pavilion angle: 41.6%
girdle thickness: thin-slightly thick(faceted) 3%
Culet: none

Any info that I missed out pls advice. Thanks all!

I don't think AGS would grade that one with ideal proportions. It is low on the crown and deep on the pavilion.

[berrysweet050777]

Hi

If its low on crown & deep in pavilion, does it mean to say that the diamond may not sparkle at certain angles when seen under normal light or low light ?
The saleman keep telling me that the diamond has alot of fire...What does he mean ? Whats should be the ideal crown height & pavilion depth then based on your expertise for this diamond . Thanks!

[davidelevi]

The salesman of course wants to sell you the diamond.

Fire is the coloured light that is reflected/refracted by the diamond.

[LaurieH]

berrysweet050777, on 17 February 2011 - 02:28 AM, said:

Hi

If its low on crown & deep in pavilion, does it mean to say that the diamond may not sparkle at certain angles when seen under normal light or low light ?
The saleman keep telling me that the diamond has alot of fire...What does he mean ? Whats should be the ideal crown height & pavilion depth then based on your expertise for this diamond . Thanks!

Fire is one of the three things used when assessing a Cut Grade for a round brilliant diamond, and it is the red/yellow/blue prismatic color refracted/reflected on/through the facets of the diamond. The other two factors are Brilliance (which is how much light/dark areas there are visible when the diamond is held still) and Scintillation (which is a fancy word for "sparkle" and the whole light/dark thing when the diamond is rocked and tilted). Diamonds should display pretty good fire and scintillation if they're well cut, but often individual diamonds will display more of one or the other. Then it just comes down to preference

[berrysweet]

Hi All

The described diamond that I bought.....

[berrysweet]

[davidelevi]

Congratulations, and thanks for coming back to show us your ring!

It looks very large for a 1 carat; is this the same stone you described above? Or do you have very slim fingers?

[berrysweet]

davidelevi, on 05 March 2011 - 11:35 PM, said:

Congratulations, and thanks for coming back to show us your ring!

It looks very large for a 1 carat; is this the same stone you described above? Or do you have very slim fingers?

Yes its the ring that I described above....i guess the setting plus I have quite slim fingers