CUT What does Newbie need to know about cut?

[mgpatsfan]

I am going to buying a round diamond to be placed in platinum or white gold.

I have a $5000 total budget. I am looking at a lot of posts and all of the stuff on cut is very important but confusing.

WHAT DO I NEED TO KNOW?

Much thanks!!

 

[yssie]

Check out the tutorial under "knowledge" at the top of the page, that''s a great place to start

 

[kenny]

Yes, as yssie says read the Advanced Tutorial under KNOWLEDGE above.

But if you want a shortcut...

At the top of this screen, click on PRICES.
Select, Search by Cut
Enter:
Round
Cut: Excellent to Excellent
Enter your preferred clarity and color
Lab: GIA or AGS only

It will pull up a list of rounds with excellent cut.
Just buy one.
It will be as good as anything you'd buy after spending weeks learning about cut.

 

[legallyspoiled]

I''m still a novice at this but here is what a beginner should know, in my opinion.

Ranked from highest to lowest:
Super Ideal/Ideal (Hearts & Arrows)
Ideal/Excellent
Very Good
Good
Fair
Poor​

A diamond that is cut well will impact (i.e. improve) the appearance of color, clarity, and even how large a diamond will appear. It will look whiter and any inclusions will be less obvious. Also, the diamond will face up appearing larger than what it is. A diamond that is well cut will also have better scintillation, fire, and brilliance (i.e. SPARKLE!).

To me, having an ideally cut diamond is #1 on the list because why invest so much in a diamond if it isn''t going to sparkle like mad?! So for me, "ideal" is a given. But you have to rank your own C''s!

Here is how I rank mine:
1. Cut
2. Carat (I''m a size girl!)
3. Color
4. Clarity

 

[mgpatsfan]

Thanks so much

 

[yssie]

Date: 4/28/2010 2:14:24 PM
Author: legallyspoiled
I''m still a novice at this but here is what a beginner should know, in my opinion.

Ranked from highest to lowest:
Super Ideal/Ideal (Hearts & Arrows)
Ideal/Excellent
Very Good
Good
Fair
Poor​

A diamond that is cut well will impact (i.e. improve) the appearance of color, clarity, and even how large a diamond will appear. It will look whiter and any inclusions will be less obvious. Also, the diamond will face up appearing larger than what it is. A diamond that is well cut will also have better scintillation, fire, and brilliance (i.e. SPARKLE!).

To me, having an ideally cut diamond is #1 on the list because why invest so much in a diamond if it isn''t going to sparkle like mad?! So for me, ''ideal'' is a given. But you have to rank your own C''s!

Here is how I rank mine:
1. Cut
2. Carat (I''m a size girl!)
3. Color
4. Clarity

I respectfully disagree with this - I think a well-cut stone will perform as well to the human eyes as a true H&A, H&A is effectively a mind-clean thing. Especially since true H&A are incredibly rare - even in the popular H&A lines here on PS the diamonds aren''t completely, totally, perfectly symmetric, and the amount of acceptable variation is up to the vendor of the brand (which is why some H&A lines are considered "tighter" than others).

WF''s ES line, for example - not H&A but it would be incredibly difficult - if not impossible - to differentiate betwen a good specimen and an ACA IRL!

 

[slg47]

I think Rhino has posted some videos comparing cut that show the difference between a ''fair'' cut and an ''excellent'' cut...the cut quality really determines how much the diamond will sparkle

yay sparkle

 

[legallyspoiled]

Date: 4/28/2010 3:15:54 PM
Author: yssie

Date: 4/28/2010 2:14:24 PM

Author: legallyspoiled

I'm still a novice at this but here is what a beginner should know, in my opinion.

Ranked from highest to lowest:

Super Ideal/Ideal (Hearts & Arrows)

Ideal/Excellent

Very Good

Good

Fair

Poor​

A diamond that is cut well will impact (i.e. improve) the appearance of color, clarity, and even how large a diamond will appear. It will look whiter and any inclusions will be less obvious. Also, the diamond will face up appearing larger than what it is. A diamond that is well cut will also have better scintillation, fire, and brilliance (i.e. SPARKLE!).


To me, having an ideally cut diamond is #1 on the list because why invest so much in a diamond if it isn't going to sparkle like mad?! So for me, 'ideal' is a given. But you have to rank your own C's!


Here is how I rank mine:

1. Cut

2. Carat (I'm a size girl!)

3. Color

4. Clarity

I respectfully disagree with this - I think a well-cut stone will perform as well to the human eyes as a true H&A, H&A is effectively a mind-clean thing. Especially since true H&A are incredibly rare - even in the popular H&A lines here on PS the diamonds aren't completely, totally, perfectly symmetric, and the amount of acceptable variation is up to the vendor of the brand (which is why some H&A lines are considered 'tighter' than others).


WF's ES line, for example - not H&A but it would be incredibly difficult - if not impossible - to differentiate betwen a good specimen and an ACA IRL!

I don't understand what you are disagreeing with. Is a H&A not better cut than an excellent or good diamond? If they were the same, they wouldn't be graded as an ideal. I've seen H&A (also known as an ACA) and I've seen excellent and good diamonds IRL...and there is a difference. There is a reason that people pay a premium for ideally cut diamonds. The H&A far out performed the lower graded diamonds.

From the Whiteflash website..."After meeting proven AGS ideal parameters Whiteflash ACA is taken much further."

Also, if you look at an AGS report, they rank cut as:

Highest to Lowest:
Ideal
Excellent
Very Good
Good
Fair
Poor​

Also, if you look at a GIA report, they rank cut as:

Highest to Lowest:
Excellent
Very Good
Good
Fair
Poor​

What is there to disagree with??

 

[stone-cold11]

Date: 4/28/2010 4:38:27 PM
Author: legallyspoiled
I don''t understand what you are disagreeing with. Is a H&A not better cut than an excellent or good diamond? If they were the same, they wouldn''t be graded as an ideal. I''ve seen H&A (also known as an ACA) and I''ve seen excellent and good diamonds IRL...and there is a difference. There is a reason that people pay a premium for ideally cut diamonds. The H&A far out performed the lower graded diamonds.

From the Whiteflash website...''After meeting proven AGS ideal parameters Whiteflash ACA is taken much further.''

Also, if you look at an AGS report, they rank cut as:

Highest to Lowest:
Ideal
Excellent
Very Good
Good
Fair
Poor​

Also, if you look at a GIA report, they rank cut as:

Highest to Lowest:
Excellent
Very Good
Good
Fair
Poor​

What is there to disagree with??

Nope. Different grade assignment, an AGS0 Ideal will be at best a GIA Ex, there is just no better grade on the GIA scale, it can even be lower, a GIA VG. Similarly a GIA Ex can be an AGS Ideal or much worse, grade each stone on it''s own merit and not not the grade assigned to it by the lab.

As defined, H&A is just a measure of optical symm, and that is just a subset of nice optical symm, it has nothing to do with cut performance. A stone with nice H&A pattern can be a bad performer, lots of like leakage in the IS image, if the proportions are not complementary.

 

[yssie]

legallyspoiled,


H&A stones are cut to specific requirements - ACAs, for example, are all AGS0 and have other requirements, whereas AGS1 stones can be Infinity H&As, and I regard both these brands equally highly.


All the H&A brands I can think of do require stones be of high cut grade by AGS or GIA.


HOWEVER you can certainly have a beautiful stone with top light return that does not exhibit the perfect optical symmetry that a H&A stone is known for. The definition of H&A is simply that - perfect optical symmetry, the presence or absence of perfectly formed hearts and arrows says little to nothing about performance. You can have a leaky H&A. I posted this summary in another thread:


Precision cutting to achieve H&A results in perfect optical symmetry. This means only that the faceting is such that if one takes a radial cross section, one will find that perfect symmetry (in addition to meet point symmetry as noted on lab certs). The presence of this optical symmetry itself - all these tiny mirrors in perfect alignment - does not in any way guarantee excellent light return, it guarantees symmetric patterning and a level of symmetry in the primary light output of those facets, because that's what optics physics dictates. You can certainly have a diamond that maximally outputs light without this perfect symmetry in faceting; statements like the above are misleading in that they ascribe to the existence of H&A performance effects that are actually the direct results of the other requirements of a brand of H&A diamond. Purchasing a diamond that has been precision cut to achieve H&A and that also satisfies the other angle and proportion requirements of most H&A brands (infinity, ACA, GOG sig., BGD H&A, HOF...) is an easy way to get a top performer, but there's no causal relationship between the two.


People pay more for H&A because A) it's an easy way to guarantee an excellent performer, as long as you choose a respected brand, and B) having perfect hearts and arrows is a mind-clean thing for some people.


ETA: SC got there first

 

[legallyspoiled]

Date: 4/28/2010 5:00:52 PM
Author: yssie
legallyspoiled,



H&A stones are cut to specific requirements - ACAs, for example, are all AGS0 and have other requirements, whereas AGS1 stones can be Infinity H&As, and I regard both these brands equally highly.



All the H&A brands I can think of do require stones be of high cut grade by AGS or GIA.



HOWEVER you can certainly have a beautiful stone with top light return that does not exhibit the perfect optical symmetry that a H&A stone is known for. The definition of H&A is simply that - perfect optical symmetry, the presence or absence of perfectly formed hearts and arrows says little to nothing about performance. You can have a leaky H&A. I posted this summary in another thread:



Precision cutting to achieve H&A results in perfect optical symmetry. This means only that the faceting is such that if one takes a radial cross section, one will find that perfect symmetry (in addition to meet point symmetry as noted on lab certs). The presence of this optical symmetry itself - all these tiny mirrors in perfect alignment - does not in any way guarantee excellent light return, it guarantees symmetric patterning and a level of symmetry in the primary light output of those facets, because that''s what optics physics dictates. You can certainly have a diamond that maximally outputs light without this perfect symmetry in faceting; statements like the above are misleading in that they ascribe to the existence of H&A performance effects that are actually the direct results of the other requirements of a brand of H&A diamond. Purchasing a diamond that has been precision cut to achieve H&A and that also satisfies the other angle and proportion requirements of most H&A brands (infinity, ACA, GOG sig., BGD H&A, HOF...) is an easy way to get a top performer, but there''s no causal relationship between the two.




People pay more for H&A because A) it''s an easy way to guarantee an excellent performer, as long as you choose a respected brand, and B) having perfect hearts and arrows is a mind-clean thing for some people.



ETA: SC got there first

I think you missed my point. My point was to make clear the rankings of the cut. I put (Hearts and Arrows) in parens because that is where they fall.

 

[yssie]

If your point wasn't that H&A stones are 'better cut' than ideals, then SC and I have both missed your point. If that was your point, I disagree with it.



In any case, there's no such thing as a higher grade beyond AGS0 (and only stones with ID sym/pol can make the 0 cut grade, Exs get demoted to AGS1 which is why some AGS1s can be fantastic purchases since they don't carry the AGS0 premium but are cut to the same tight specs) or GIA Ex (which allows vg sym/pol).



We should probably take this discussion to another thread though, I doubt we're helping the OP

 

[legallyspoiled]

Date: 4/28/2010 5:08:56 PM
Author: yssie
If your point wasn''t that H&A stones are ''better cut'' than ideals, then SC and I have both missed your point. If that was your point, I disagree with it.

Again, I was only attempting to make it clear that H&A fall within the Ideal category. However, some vendors (i.e. Whiteflash) sometimes refer to their ACA/H&A as "super" ideal. Also, it can be a bit confusing discerning whether there is a diff between the GIA and AGS cut grading.

My apologies for unintentionally "thread jacking" your post. Also, my apologies if this exchange has confused you even more!