The Diamond Cut – How to Maximize Your Diamond’s Sparkle

I think we can all agree that we’re captivated by diamonds simply because of THE sparkle! No other gem can radiate like a diamond does. It’s like a reachable, wearable star that connotes a timeless bond. And the head honcho behind this mesmerizing shimmer is what we call theDiamond Cut.

Now, a lot of you may have heard of round cut, princess cut, and other diamond shapes that are tailed by the word “cut“. Well, it’s just like a childhood nickname you can’t get rid of! But that’s not really what Diamond Cut is all about.

What I mean by Cut is the proportions of the diamond that determine its level of sparkle. Or in gemological terms: its fire, brilliance, and scintillation. (You’ll be seeing these terms down the line, so better get used to it. 🙂 ) While the Diamond Shape only refers to the outline of the stone.

These diamond shapes have nothing to do with the diamond cut.

Unlike the superficial impression on diamonds and the in-your-face depiction of shape, the diamond cut is technical, measurable, and adjustable to maximize your gem’s brilliance! In fact, the cut is the ruler of the Diamond 4Cs – cut, color, clarity, and carat weight.


Cut is Always King!

Before I begin, please bear in mind that the diamond cut only refers to the proportions of the round and princess cut gems. Therefore, you will not find any cut grades for other diamond shapes.

 

Diamond Cut Proportions

Now, the picture on the left depicts the relationship between various facets and angles that play as decisive factors in determining the diamond’s cut.

A proportioned cut will let the light traverse through the diamond in such a way that it will be reflected back to the viewer’s eye and give boost to the other 4Cs.

 


The Diamond’s Light Performance

In fact, a well cut diamond will reflect more light and appear larger than it actually is. It can also make the face-up color look brighter, and at the same time, mask or camouflage inclusions. This is because a well cut diamond has greater brilliance, fire, and scintillation that can easily conceal flaws.

Shine Bright Like a Diamond

 

Here’s the Science of Sparkle in a Nutshell:


  • Fire – The light dispersion that appears as flashes of rainbow colors. It’s beautifully seen on darker environments like at a candlelit dinner.
  • Brilliance – The light reflected in and out of the diamond. Having perfect proportions will prevent light leakage and thus, make the gem appear brighter.
  • Scintillation – The pattern of dark and light facets that intensely sparkles when the diamond is moved. It’s usually seen in office lighting environments – opposite of where fire can be seen.

See the difference between a perfect cut and an inferior cut in action by comparing these gems:

PERFECT CUT - 1 CARAT G-VS2 TRUE HEARTS IDEAL DIAMOND

TRUE HEARTS IDEAL – 1 CARAT G-VS2

INFERIOR CUT - 1 CARAT G-VS2 GOOD CUT ROUND DIAMOND

GOOD CUT – 1 CARAT G-VS2 ROUND

By clicking the images, you can actually view the diamonds from all sides and see how they differ in light reflection. The one on the left is within super ideal cut proportions and exhibits a lot of sparkle. The diamond on the right however, looks much less lively and exhibits considerably less sparkle.

Another important factor in deciding how well the light will reflect back to the viewer is the pavilion angle. If it’s too shallow or too steep, it will then cause less light return.

Light performance of a diamond according to the diamond cut

Apparently, everybody wants brilliance (white light) and fire (rainbow color light) in a diamond. But if for instance, you have a preference for fire, you can deliberately choose one that maximizes fire. In such a case, you would have to find a so-called “fiery ideal cut diamond”.

Take a look at these 1 CARAT G-VS2 EXCELLENT CUTs below:

Fire 1 CARAT G-VS2 EXCELLENT CUT ROUND DIAMOND
No Fire 1.01 CARAT G-VS2 EXCELLENT CUT ROUND DIAMOND

The diamond on the left exhibits much more fire than the diamond on the right. The second gem looks great, but it is maximized for brilliance and not fire. Of course, you will only be able to see the difference if you view them from all sides just as you would in real life.

What the examples above are meant to show you is how much of an impact the diamond cut has that it should be your absolute priority in choosing a diamond. You may compromise on everything else, especially on color and clarity, but you should never compromise on cut!


So, Why Do Poor Cut Diamonds Exist?

You would think that people wouldn’t be interested in buying poor cut diamonds where fire, brilliance, and scintillation hardly exist. After all, this is what we buy diamonds for!

Diamond cut from the rough

But in reality, poor cuts exist for various reasons:

Obviously, people will pay the most attention to the carat weight as it’s usually the first thing you’ll be asked about upon being engaged.

Thus, the prices sharply increase for bigger carat weight than for a better cut. For this reason, many diamond cutters are intent on preserving as much weight during the cutting process.

If a cutter produces a deeply cut gem, more weight will be hidden in the diamond. And it will drive the carat weight and the price higher! Yes, the cut grade will go down, but in most cases, it pays more for the cutter to opt for a bigger carat.

Furthermore, it also happens very often that diamond cutters would want to eliminate a striking inclusion. They do so by cutting it out. But since they also want to preserve more weight, they would risk the diamond cut quality being reduced.


The Different Cut Grades – Which Grade to Choose

Some first-time seekers are duped by fake or unreliable grading reports because they don’t know that you should only look for gems graded by GIA or AGS.

Diamond certificates from other grading companies, especially in-house grading reports, are not as accurate and consistent as the said labs. So, to avoid the hassle, simply filter your diamond search with GIA or AGS stones.

GIA and AGS cut grades

An AGS 0 isn’t equivalent to a GIA Excellent. Still, they’re both great indicators for cut quality. My top recommendation is to go for the best cut! This means that you should choose a GIA “Excellent” or an AGS “Ideal”. In my opinion, the diamond cut is the wrong place to try to save money!

You should only do so on color and clarity as they don’t need to be the highest grades to be the best.

Now, if you are really tight on budget, it’s okay to choose “Very Good” for GIA diamonds or “Excellent” for AGS. These grades will still be good, but the increase in brilliance when going for the best cut grade is, of course, much noticeable.


Visible Differences Between Cut Grades

Diamonds with lower cut grades usually look worse than diamonds with higher grades.

Here’s how each rating differ:

Excellent/Ideal

1.00 CARAT G-VS1 EXCELLENT CUT ROUND DIAMOND Exhibits optimal fire and brilliance as virtually all the light that enters is reflected by the diamond to the viewer’s eye.

Very Good

1.00 CARAT G-VS1 VERY GOOD CUT ROUND DIAMOND When seen from the top-down view, it can show an asymmetrical pattern of light and dark spots. It can also show dullness.

Good

1.00 CARAT G-VS1 GOOD CUT ROUND DIAMOND Good Cuts don’t reflect light as much as the higher grades because their fire, brilliance, and scintillation are not up to par.
Fair FAIR CUT DIAMOND

This cut grade doesn’t retain the light entering the diamond, so the perceived fire and brilliance is greatly reduced.

Poor POOR CUT DIAMOND

Poor Cuts are dull even when seen without magnification tools. It’s completely worthless and is a bad value for money.

Note: Fair and poor cut grades are so disastrous that most shops don’t even sell them!

Another thing you have to bear in mind is that there can be considerable differences between diamonds with the same cut grade. Check out the comparisons below!


Excellent Cut Round Diamonds

Both diamonds below are graded “Excellent” by GIA. The one on the left has perfect proportions, while the second diamond’s table is too wide making it reflect less light.

EXCELLENT CUT - 1 CARAT G-VS2 ROUND DIAMOND

EXCELLENT CUT – 1 CARAT G-VS2

EXCELLENT CUT 2 - 1.00 CARAT G-VS2 ROUND DIAMOND

EXCELLENT CUT – 1 CARAT G-VS2


Very Good Cut Round Diamonds

The next two diamonds below are both graded “Very Good” by GIA. The one on the left has exceptionally good proportions for its cut grade. The gem on the right, on the other hand, might be considered below average for the “Very Good” cut grade. While it’s still an acceptable choice, I would recommend opting for the diamond on the left.

    • VERY GOOD - 1 CARAT G-VS2 CUT ROUND DIAMOND

      VERY GOOD CUT – 1 CARAT G-VS2

    • VERY GOOD 2 - 1 CARAT G-VS2 CUT ROUND DIAMOND

      VERY GOOD CUT – 1 CARAT G-VS2


Good Cut Round Diamonds

The next two diamonds are “Good” cuts. The one on the left is poorly cut and the diamond on the right is a complete mess. Thus, none of these diamonds are acceptable.

GOOD CUT - 1 CARAT G-VS2 ROUND DIAMOND

GOOD CUT – 1 CARAT G-VS2

GOOD CUT 2 - 1 CARAT G-VS2 ROUND DIAMOND

GOOD CUT – 1 CARAT G-VS2

As you can see, even if two diamonds share the same grade, they don’t have to appear the same. This is because GIA and AGS allow a certain level of variation as long as it’s within the specific grade.

You’d probably deem symmetry as the more evident distinction and assume that it causes the rise and fall of cut quality. But a diamond that isn’t symmetrical can still be brilliant as most of the diamond’s brilliance is produced by the cut and not the symmetry.

An excellent cut and an excellent symmetry go hand in hand. But it’s mainly the proportions between different parameters that determine the diamond’s brilliance. And knowing of these proportions will let you find the best diamond within the same cut grade. It’s high time we delve into these features!


The Diamond Anatomy – Explained by GIA

GIA Cut Proportions

Table Size The top horizontal facet of the diamond.
Total Depth The diamond’s overall depth from the surface of the table to the culet.
Pavilion Depth The lower portion from the bottom edge of the girdle to the culet.
Pavilion Angle It is the average of the angles formed by the diamond’s pavilion main facets and its girdle plane.
Crown Height The upper portion, from the top edge of the girdle to the table.
Crown Angle The angle that’s formed where the bezel facets meet the girdle plane.

Star Length

 

The horizontally projected distance from the point of the star facet to the edge of the table, relative to the distance between the table edge and the girdle edge.
Girdle Thickness The middle portion of a diamond, a narrow section separating the crown from the pavilion, and functions as the diamond’s setting edge.
Lower Girdle This ratio is measured by calculating how long the lower girdle facets are relative to the length of the pavilion.
Culet The small facet at the bottom intended to prevent chipping and to the point.

Now, all these parameters must lie within certain limits to get a specific cut grade. Our grading system today is very close to the Tolkowsky Ideal Cut which was introduced by the mathematician and renowned gemologist Marcel Tolkowsky in 1919.

The Tolkowsky Ideal Cut

He published his findings for the perfect diamond proportions in his thesis entitled “Diamond Design, A Study of the Reflection and Refraction of Light in a Diamond.”


Tolkowsky Ideal Cut 2

Today’s Standard Diamond Grading System

Nowadays, GIA and AGS have slightly modified Tolkowsky Ideal Cut’s proportions for diamonds with Excellent/Ideal light performance.

You can find the values on the right.

Although please bear in mind that these values should be used as a basic guideline. If you want to know the perfect parameters specifically for a round cut, please read my post on round diamonds here.

 

Excellent proportions for a round cut diamond

And if you happen to have your diamond’s parameters at your disposal, I would advise to type in these proportions into the free GIA facetware tool.

This will quickly tell you what cut grade GIA would rate your diamond!

The proportions on the left usually serves a diamond with an Excellent/Ideal cut grade (AGS is stricter than GIA in cut grading).

 

However, if you want to have a super ideal cut, then take note of these parameters:

Proportions for super ideal cut diamonds


Viewing the Diamond Sparkle in HD

As light travels in and out of the diamond and springs back into the eye of the beholder, the “bling factor” is then created. It’s great to know of the specific proportions, but it’s also paramount to view your diamond and inspect it from all angles.

Diamond Cut Sparkle 2

Currently, James Allen is the only diamond vendor that will allow you to view diamonds in 20x magnification through their revolutionary 360° video display technology. Another fascinating thing is that their advanced filter tool can turn the intricacies of diamond hunting into just a few taps!


What’s Next?

Aside from cut grades, gemological labs also bestow ratings for symmetry and polish. They’re assigned apart from the cut grade, but they also have a huge impact on your gem’s overall beauty!

Read Next: Diamond Symmetry

Should you have any questions about Diamond Cut, let me know in the comments section below.

Or might as well write to me, my advice is free. 🙂

 

The Diamond Cut – How to Maximize Your Diamond’s Sparkle
3.3 (66.83%) 164 votes

About 

Sebastian Naturski loves to write about diamonds and share his knowledge with his readers.
When he is not working on his website he is studying law at Humboldt University of Berlin.
He has taken part in several international law competitions and likes to broaden his horizons.
His other big passion are languages. He is fluent in German, English, Polish and Japanese and got basic skills in French and Spanish as well.

62 Comments

  1. Hi Sebastian
    Thanks for all the tips on your website. We were just at a jeweler’s and have decided on this diamond (GIA excellent) but after researching, have noticed that it’s slightly outside of your recommended specs. Appreciate your advice if this is a good diamond to get and if we will be compromising on the brilliance and fire. Thanks!

    Depth: 62.3 %
    Table: 58 %
    Crown Angle: 36.0°
    Crown Height: 15.0%
    Pavilion Angle: 40.8°
    Pavilion Depth: 43.0%
    Lower Half: 80%
    Girdle: Slightly Thick, Faceted, 4.0%
    Culet: None

    • Hi Jan,

      I suggest you keep looking. It doesn’t have to be super ideal, but at least look for standard cut proportions. Especially for the crown and pavilion angles. That’s if you want better quality and more brilliance. But if the diamond looks good to you despite slightly off proportions, it’s still your choice at the end of the day. 🙂

    • Hi Patrick,

      It’s within super ideal cut proportions, good job! Although bigger diamonds tend to adapt more body color. So, if you’re going to use a white gold setting, just make sure the G color in a 2-carat diamond looks good to you. If the color does show and you want to stick with G, you may opt for a yellow gold ring and it will make your diamond appear whiter than it is. 🙂

    • Hi Abby,

      The diamond has super ideal cut proportions if not for its slightly thick girdle, but an exquisite diamond nonetheless!

  2. Hi Sebastien
    Is a high quality cut as important for other diamond shapes, such as emerald and marquise? How would I be able to tell the quality of the cut for emerald and marquise shapes? Thank you!

    • Hi Pam,

      Yes, cut will always be the most dominant factor in any diamond shape’s 4Cs, but to achieve the best possible sparkle for fancy cuts, you must also opt for high clarity and color grades since these shapes tend to reveal more body color and flaws. There are no cut grades by GIA for such shapes. But you may refer to my recommended proportions below for reference:

      EMERALD CUT
      Recommended Proportions | Most Affordable Proportions
      Table % – 61% – 68% | 59% – 70%
      Depth % – 60% – 65% | 57% – 68%
      Girdle – Very Thin – Slightly Thick | Very Thin – Slightly Thick
      Culet – None | Very Small

      MARQUISE CUT
      Recommended Proportions | Most Affordable Proportions
      Table % – 53% – 63% | 52%
      Depth % – 58% – 62% | 56% – 57.9%
      Girdle – Very Thin – Slightly Thick | Very Thin – Thick
      Culet – None | Very Small

        • Hi Judy, please refer to the dimensions below:

          Oval Cut Diamond
          Recommended Proportions | Most Affordable Proportions
          Table % – 53 – 63 | 52
          Depth % – 58 – 62 | 56 – 57.9
          Girdle – Very Thin – Slightly Thick
          Culet – None | Very Small
          L/W Ratio – 1.35 – 1.50 | 1.30 – 1.34

    • Hi Zee,

      What you should be taking note of are the crown and pavilion angles as they’re the biggest contributors in the diamond’s sparkle. And upon checking your diamond’s specs, its proportions reveal that it is a super ideal cut except for the girdle, but still an exquisite diamond nonetheless. Just make sure that it’s eye clean.

  3. HI Sebastian, I’m trying to decide between GIA 2238801731 and 6242029719. We saw them in the store and the smaller one 1.3c had visually less color than the 1.4c but only when compared next to each other. The price is only different by a couple hundred so i can go either way. Let me know your opinion on what would look best to the naked eye on a 6-prong solitaire setting.

    • Hi Sandy,

      The crown angle and pavilion angle are the most important features in determining the light performance of a diamond. The most balanced combination (in terms of brilliance and fire) would be 34.5° as a crown angle and 40.8° as a pavilion angle. We have 2238801731 with a 36.0° crown angle and a 40.6° pavilion angle, and then we have 6242029719 with a 33.0° crown angle and a 40.8° pavilion angle. The 36.0° crown angle is very steep and the 33.0° crown angle is very shallow.

      For a steeper crown angle, you want a shallower pavilion angle, and for a shallower crown angle, we would want a steeper pavilion angle. In this particular case, the steep crown angle of 36.0° is counterbalanced by the shallower pavilion angle of 40.6°. The other diamond with the shallow pavilion angle of 33.0° is not so well counterbalanced by the medium pavilion angle of 40.8°. Also, if in doubt, a steeper crown angle is to be preferred. The overall light performance of Diamond 2238801731 should therefore be better.

    • Hi Dave,

      The HCA is just a rejection tool, not a selection tool. We only use it to weed out poor performing diamonds. That’s a super ideal diamond you got there!

    • Hi JL,

      Although it has a slightly thick girdle, it is within the super ideal cut proportions, and it scored 1.4 in the HCA tool which means it has excellent visual performance. And compared to other diamonds with the same specs on James Allen, your diamond bears a better price and symmetry.

  4. Hi Sebastian,
    Thanks for very useful information. I’m choosing a 1-carat solitaire for my proposal and looking forward to your advice on which diamond I should get. I had 3 options of:
    1. https://www.gia.edu/report-check?reportno=2156154257
    OR
    2. https://www.gia.edu/cs/Satellite?reportno=5256401787&c=Page&childpagename=GIA%2FPage%2FReportCheck&pagename=GIA%2FDispatcher&cid=1355954554547&encryptedString=21CF9EE8FCC7B89A7B345B2DBDE9287A&qr=null
    OR
    3. https://www.gia.edu/report-check?reportno=6251251983
    If my key decision making driver is the cut factor and how brilliant the diamond is under the light, can you please suggest me which diamond should I choose base on those reports? Since I’m gonna by online, so can’t compare these 3 diamonds in person.
    Thank you very much.

    • Hi Jimmy,

      All three have ideal dimensions, but diamond number 2’s proportions fall within the super ideal cut parameters. I would still recommend viewing the diamond in HD imagery, if not in person, so you’ll really know what you’ll be getting. Goodluck!

  5. Hi Sebastian, which would you choose, James Allen, SKU 2514539 o r2514542 thanks floyd

    • Hi Floyd, I would choose 2514539 as it has a more proportioned depth which also makes it super ideal in all aspects.

  6. how do you explain in simple terms that GIA excellent – ideal – and others may not be true hearts and arrows, to sales at different web sites or do they know and keep pushing their cut.

    • Hi Floyd,

      Hearts and Arrows diamonds represent the pinnacle of cut precision. A diamond can bear super ideal cut proportions, but to be labeled with the H&A pattern, it also has to have superior light performance from precise optical symmetry. It’s true that there are unreliable vendors that brand their stones as H&A even if it’s not passable, but websites like James Allen have a separate filter for H&A diamonds, and most legit shops would provide you with ASET, Idealscope, H&A images to justify the name.

  7. Sebastian!

    My diamond is 1.05 Emerald Very Good Cut with G color & IF clarity. Is it OK to go with Very Good Cut instead of Excellent? This ring has the specs I like, so I am leaning toward this one, but know cut is important & don’t know how different a VG vs. Excellent would be in this case. Also, polish is Excellent and Symmetry is VG.

    Thank you!!!

    • Hi Laura,

      We always opt for Excellent/Ideal cuts because they exhibit the most amount of fire, brilliance, and scintillation. Your diamond will sparkle better if it has the best cut. Maybe you can watch your diamond in 360-degree view and compare it to the light performance of an Excellent cut, and then decide if you would still want to stick with the VG cut. If you’re satisfied with its sparkle and it’s eye clean, VG is okay. 🙂

  8. Hi,
    Would you get a .70 round F, VVS1, Super Ideal with GIA cert and a Table of 56%, no girdle, no cutlet, florescence none and a depth of 62.8% for $3562

    OR

    A .70 round G, VVS1, Super Ideal with GIA cert and a Table of 58%, no girdle, no cutlet, florescence none and a depth of 62.3% for $2996

    • Or

      .73 round F, IF, Super Ideal with GIA cert and a Table of 58%, no girdle, no cutlet, florescence none and a depth of 61.7% for $4028

      • Sorry last question. Also for the ring, does it make sense to pay $450 for better side diamonds? They are very small.

        The ring is a 14k rose gold using white diamonds 1/2 way down the shank that are VS/F-G grade diamonds is $2,189. If you want to use SI/H-I grade white diamonds instead, the price is $1,745.

        Would it depend on how good the color of the center stone is?

        • Hi Brian,

          The first diamond is closer to the super ideal proportions of table (54%-57%) and depth (61%-62.5%) and I would initially go for the best cut possible. But if you’ll compare the first and second diamonds and don’t notice any difference in fire, brilliance, and scintillation, then you may opt for the second one since G color is also bright and is much cheaper.

          For the second question, since the setting is rose gold, it’s okay to use lower graded side diamonds, as long as the center stone appears whiter. The side stones should always be a bit darker than the center stone, so they can accentuate the brilliance. 🙂

  9. Hi.
    F color vs1 very good cut Gia certified 1 carat diamond
    D color si 1 excellent cut Gia certified 1 carat diamond
    Which one would be better choice?
    They are about same price in my budget.
    I could go for G color and vs clarity with excellent cut but I want to have colorless diamond.
    Please let me know your opinion. Thank you.

    • Hi Sunny,

      The golden rule is to opt for the best cut possible, so the second option seems to be a better choice, especially if they are price the same. Just make sure that it’s eye clean, since it’s SI1. Although, I would still recommend a G-VS with excelelnt cut because a G colored diamond will look as colorless as a D when set on a ring.

  10. Hello sebastian,
    You can’t imagine how did you save my a** yesterday from being cheated. That is because i just had a quick look on your articles few minutes before payment.. thanks a lot.

    Currently, i gotvan offer for a loose diamond h color, vs1, cut and sym excellent, pol is vgood. Flur is none. Depth and table are within range. But girdle thickness is slightly thick.

    Does girdle thickness would have big impact on the quality? Or these specs are for good quality stone ? The diamond price by the way is 3300 $

    • Hello Karim,

      Glad to be of help! 🙂 Girdle thickness is important because if it’s thin or extremely thick, it would make the diamond prone to chipping. According to GIA’s Girldle Assessment, as long as your gem has a thin/medium – slightly thick girdle, it could receive an excellent cut grade. All your other specs are of high quality, just make sure your stone is eye clean.

      Unfortunately, I won’t be able to compare prices without your carat weight info. Why don’t you type in your specs in James Allen’s filter tool to see how much diamonds are priced with your 4Cs? Let me know how it goes!

  11. Your ports are very helpful. Can you explain what’s important for cushion cut diamonds? I am currently looking at 1 caret with H color VVS2. Also how does cushion modified brilliant differ from standard cushion cut.

    • Hello HH,

      Glad to be of help! For cushion cut diamonds, make sure that the table and depth is 61-67, the girdle is thin to slightly thick, and there’s no culet. The most popular legth to width ratio is 1.10 to 1.20. And since it’s 1 carat, it’s best to go for the D-F color range, and FL to VVS2 for clarity.

      There’s also what we call cushion brilliant based from the faceting of round brilliant cuts. Since it resembles the super ideal shape, it’s deemed more popular than the standard cushion cut and the cheaper cushion modified brilliant that bears a crushed ice appearance.

  12. Hi Sebastian,
    I have found your site very informative. I was wondering if you could please give advice/your opinion on the two diamonds below?
    GIA #7211555932 https://www.gia.edu/report-check?reportno=7211555932 (also comes with a GSI light analysis report http://wg.gemscience.net/PDF/H15077800502.VVIMIOSPNB.pdf –excellent for brilliance, fire, scintillation, and contrast effect, and very good for efficiency)
    AGS #104046879034 carat=2.018 http://www.agslab.com/pdf_sync_reports/104046879034-PDQDFK.PDF
    Note: The diamonds both look beautiful in person. The GIA, SI1 is eye clean. But, both don’t seem to fit 100% into the varying ideal proportions listed online…and I am getting so confused. Any help would be much appreciated.
    Thank You,
    Farah

    • Hi, Farah!

      Thanks for your feedback. 🙂 If you’ll go back to my super ideal round cut proportions in this article, you’ll see that the GIA diamond has better crown angle and pavilion angle proportions. Cheers!

  13. Hi There,
    So I was helping my son look for a diamond for his GF
    We looked at a princess cut diamond he really likes its a GIA D ,vvI (I think) but sematry was fair should he stay away?

    • Hi there, Deb!

      The golden rule is to choose Excellent/Ideal cut diamonds to achieve superb sparkle. And a diamond with an excellent cut has to have “Excellent” or at least “Very Good” symmetry as well.

      That said, I would advise you to go for a “Very Good” symmetry grade. These diamonds include symmetry flaws that can only be seen face-up at 10X magnification. While diamonds with only “Good” symmetry grades might exhibit flaws that can be viewed by the naked eye. Such diamonds will never receive an “Excellent” cut grade. What more for “Fair” symmetry grades, right?

      Please have a look at this article to know more about the right symmetry and the perfect cut. Cheers! 🙂

  14. What are your views on buying a d colour emerald cut diamond, .80 ct, vvs2 clarity.

    • Hi Sheila, I would always recommend a G color and an Eye Clean VS2 clarity if you want to get the biggest bang for your buck without compromising quality. 🙂

  15. Hi,

    Since only round and princess cut diamonds have cut grades, is there anyway to determine how well cut a pear shaped diamond is, for instance?

    Thanks!

  16. Hi,
    Do you recommend buying from bluenile or a local dealer? I heard Blue Nile marks up 20% compared to actual stores.

    Thank you

    • Hey Art,

      I haven’t heard of the 20% markup, but diamonds bought at Blue Nile are cheaper than diamonds bought at a brick and mortar store because they have lower operating costs. Thus, I would prefer Blue Nile to a local dealer. I aslo recommend other online shops like James Allen because of better functionality including high definition videos. Blue Nile recently introduced a 360-degree diamond view, but it only applies to a small percentage of their collection.

      Hope this answers your question, cheers! 🙂

  17. I’m looking at a GIA CERTIFIED G color, FL, EX cut, EX polish, EX symmetry, 1/2 CT round brilliant stone. At the store & at church it sparkles like nothing I’ve ever seen. In regular daylight, it doesn’t do much. Nor does it seem to do much in regular everyday lighting: office, living room, cloudy day, etc. What am I missing? Where is the sparkle, the brilliance, the wow? Just for reference, my numbers are: depth 61.8, table 55, crown angle 34.5, pavilion angle 40.8, girdle medium. Where did I go wrong?

    • Hi Marylin,

      I think that it has ideal proportions. A 34.5° crown angle combined with a 40.8° pavilion angle are as good as it gets. It definitely maximizes both brilliance and scintillation and thus, it should be a really sparkly diamond.

      The thing is, diamonds always sparkle best at jewelry stores because they tend to maximize the instore lighting. And direct sunlight isn’t the best lighting for excellent cuts, but it can make average or poorly-cut gems look outstanding.

      Also, the slightest bit of grease or dirt on a diamond will change the way it reflects light and greatly dim its sparkle. But what you can do is, you can clean your diamond with dish soap and a toothbrush every day to achieve maximum brilliance.

      Let me know if that helps. Cheers! 🙂

  18. Hello Sebastian, I am suprised not to find the very important baguette shape on your page? Why don’t you mention it?
    Kind regards from Colmar
    Alexandre

    • Hi Alexandre,

      thanks for your question!

      Up till now I was mainly concentrating on round cut diamonds because they are the most popular. But I will get around to writing on the baguette shape within the next week!

      Cheers!

      Sebastian

  19. Thank you for sharing this wealth of information on the diamond cut!
    I will make sure to get the best possible cut.

    Best wishes,
    Lee Hale

  20. Hi Sebastian,
    I know that the diamond cut is very important. Do you think GIA or AGS graded diamonds are better?

    • Hallo Beverly,
      in fact AGS is a little bit stricter than AGS for giving its highest cut grade. However, GIA is generally stricter in terms of color and clarity. You can make sure that your diamond has a really good cut by making sure that is is within the super excellent proportions. However, it will be difficult to make sure on your own what kind of color grade your diamond has. As GIA is stricter in terms of color and clarity I would prefer to go for a GIA graded diamond. However, both GIA and AGS graded diamonds are absolutely fine!

  21. What about GIA triple excellent graded diamonds? Are they the best choice with the best diamond cut?

    • Hallo Shawn!
      GIA triple Excellent graded diamonds are a strong indicator that you will not have a bad diamond. However, it is far from being sure that you got a diamond that is the best of the best. Having an excellent symmetry and polish is a very nice thing to have, however the cut proportions of the diamond will impact its beauty even more. Thus, even if you should have a GIA triple Excellent graded diamond, you should still check yourself that it is within the super excellent proportions I personally suggest for round cut diamonds:

      http://yourdiamondteacher.com/wp-content/uploads/2015/01/Super-Excellent-round-cut-diamonds.png

      In my opinion you should not blindly trust the label GIA triple Excellent but still check out whether the diamond has superb cut proportions. At least if you want to have a diamond with the maximum amount of sparle. Many GIA triple Excellent diamonds do not fall within these super excellent proportions and thus you must actively look out for them!

  22. Thanks for the post.
    What are the best diamond cut parameters for a princess cut diamond?

  23. Sebastian you have a great detailed post about the diamond cut.
    So you mean to say that I should not choose any diamond that does not lie within these excellent proportions?

Leave a Reply

Your email address will not be published. Required fields are marked *

*