How Cut Quality Affects Diamond Prices (Cost Per Carat Value)

octahedral rough diamonds

Higher cut quality requires more rough material removal and leads to higher prices.

Diamond pricing involves a very complex mechanism that revolves around many different factors. At the heart of it, the carat weight of a diamond has the strongest effect on prices because that’s the factor that most consumers look at when buying a diamond.

Besides carat weight, one other factor that influences the price of a polished diamond is cut quality. In fact, the cut of a diamond can drastically increase or decrease its value.

In this write up, we will look at how cut quality affects the value of a diamond and give you some perspective of the price differences you can expect to see.

Why Does Better Diamond Cut Quality Cost More?

diamond cost per carat

In general, you can expect the diamond’s cost per carat to increase as the cut quality improves. This is because more rough material has to be removed in order to achieve better cut proportions and symmetry when polishing the facets.

If you don’t know yet, diamonds are inherently priced by their carat weight. When more rough material is removed, the loss in carat weight for better cut quality has to be compensated with higher prices.

On top of that, there are additional costs for skilled labor and additional man-hours are required to polish an ideal cut diamond compared to a poorly cut diamond. Ultimately, economics and profitability are the main driving forces behind every cutting decision.

In the real world, it is not feasible for cutters to turn every single piece of rough into an ideal cut diamond because it will not be profitable to do so. This is the reason why the market is flooded with sub-par diamonds that are cut for weight retention and not for beauty.

And if you are wondering who on earth would buy stones with lower cut grades?

Well, the answer is definitely not me and hopefully not you as well – I want my diamonds to sparkle and be full of life. However, there are people in the market (both knowingly and unknowingly) who would still purchase poorly cut diamonds to fulfill their own budgets and carat size expectations.

From experience, I have found Brian Gavin and White Flash to offer some of the best pricing and selections when it comes to buying a super ideal cut diamond. If getting the best sparkle out of your diamond ring is something you care about, make sure you check them out!

Diamond Cost Per Carat: Good – Very Good – Excellent – Ideal Cut

The following price comparison chart is extracted using the search tool at James Allen. As you can see, there’s an incremental increase in prices when the cut rating of the diamond improves.

diamond cut price comparison

When buying an engagement ring, one of the most common mistakes beginners make is focusing their purchase entirely on carat weight. Don’t get me wrong, size does matter but it isn’t everything.

My take on this is; if a diamond is cut well, it will be visibly larger and more attractive than one that is cut badly. In most cases, a stone with a smaller carat weight can be a much better purchase than a larger one because of its visual appeal and costs.

Watch the following video of a diamond ring that was recently purchased. This diamond was handpicked for its superb proportions and symmetry. While it may cost a little more than the generic GIA 3Ex, the amount of brilliance and light return it exhibits is well worth the extra cost.



If you are interested to view full details of the diamond engagement ring above, click here to view the loose diamond listing and click here to view the setting.

Price Variances of Diamonds With Same Diamond Cut Rating

When diamonds are graded for cut quality in the gemological laboratory, you will notice that there are differences in cut quality even if the diamonds have the same exact rating. Take a look at 3 GIA graded diamonds below. They each have triple Excellent ratings in Cut Grade, Polish and Symmetry.

cost of diamonds per carat gia 3 excellent 1 carat size

You can view each listing separately with these links: Diamond #1, Diamond #2 and Diamond #3

If you were only looking at the grading reports by themselves, these 3 diamonds would appear similar on paper. In reality, there’s a massive difference in beauty and performance. The better cut diamond on the right has better contrast patterning and will display much better sparkle than the other 2.

And as you can see, there is about a 10% price difference between a top of the line GIA 3Ex and a bottom of the barrel GIA 3Ex diamond.

Cut Quality Matters: Don’t Scrimp on That!

As you can probably tell by now, I always highlight and preach the importance of cut to my readers. It is my personal belief most people will want a diamond that’s lively and not dull looking.

For people who are working with a tighter budget, my advice would be to go lower in color or clarity grades instead of compromising on cut quality. Bear this in mind, better cut will significantly improve the beauty of your diamond.

Ultimately, whatever buying decisions you make still boils down to your own preference and balancing of the 4Cs.

With all that said, I hope you had learnt something useful on the website so far. If you want to shop smart, it would require a proper analysis of a diamond’s cut quality and this goes beyond the information found in a grading report.

Take a deep breath, go for a 10 minutes break, grab a cup of coffee and then, return here to familiarize yourself with the rest of the 4 Cs. Once you are ready, I am going to reveal more insider’s tips and show you a step by step guide to choosing the best diamond within your budget.

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  1. Rebecca J.-
    February 23, 2018 at 2:44 am

    My girlfriend and I are looking at various ring options and we are doing the shopping together. So, no surprises there but at least this guarantees we find something she likes.

    What’s the differences between cathedral settings and solitaire settings? Are there any pros and cons of one over the other?

  2. Paul Gian-
    February 24, 2018 at 3:59 pm

    Cathedral settings can be classified as a subset of solitaire designs. The main differences lie in the arches of a cathedral shank while a solitaire design can refer to any type of ring design where there is only a single gemstone used in the entire piece of jewelry.

    Click here to read about a comprehensive guide to the cathedral ring setting and you should be able to find more answers there.

  3. Bob-
    December 2, 2018 at 12:01 pm

    You have a great website. I have read it extensively, but still do not feel confident about making the best possible choice. So, your offer to help is sincerely appreciated!

    My budget is in the $30K-$35K range (diamond and setting combined).

    — I am interested in either a round, radiant or cushion diamond shape.

    — The ring/setting needs to be platinum and halo/pave. Here is an example (used for describing the setting only):

    — Minimum carat weight should be 2 carats. A weight closer to 2.25-2.5 would be ideal. This should equate to about $12000 diamond price per carat.

    Please provide specific diamond recommendations from

    Thanks and I appreciate your help!

  4. Paul Gian-
    December 3, 2018 at 8:02 am

    I would love to help you but there is some information that I need to do that.

    First, you must narrow down exactly on the shape that you want to buy. A round is completely different from a radiant and is completely different from a cushion. Depending on the choice of diamond shape, there are different vendors who are good and specialize in different shapes. Otherwise, we will only end up running around in circles.

    Let me know so I can tailor a search to your needs.

  5. Bob-
    December 3, 2018 at 6:02 pm

    The reason I mentioned all three was because my girlfriend tried on all three last weekend and loved them equally. When I pressed her for a preference, she said she’d be happy with any of the three cuts and I should get the stone that represents the best value/quality for the bucks. She wants a halo setting.

    Having said that and because she does not have a preference, I am going to eliminate the round cut since the value of diamonds per carat is the most expensive.

    I have read and looked at hundreds of different articles and photos online and I can’t make a determination on which of the two remaining choices looks more appealing. So, I am going to a jeweler this Saturday to look at the radiant and cushion in person (again). Will revert thereafter.

    Thanks again,

  6. Paul Gian-
    December 4, 2018 at 11:51 pm

    The cushion and radiant cut will offer better value for money (price per carat) because they utilize less rough material during polishing. In order of general popularity, cushions are more popular than radiants in the market. I also find that cushions tend to exhibit better light performance and are cut to better standards than radiant shapes.

    If performance is what you are after, the round brilliant cut is the one that can deliver the most sparkle relative to the other shapes.

  7. Bob-
    December 6, 2018 at 2:23 am

    Paul: I went to a jeweler on jeweler’s row in Chicago. I looked at several different cuts and decided the round cut was my preferred. This is the GIA report from the one I liked the best – GIA 72156419496

    With size as an important factor, I chose to sacrifice on the clarity, in favor of a strong color rating and weight. I realize you cannot comment without actually seeing the diamond. I completely understand. However, could you please look at the below GIA and let me know if there are any red flags (on paper)? I was told that these were super ideal cut diamond proportions.

    The inclusions were not visible to my eye, but when I looked at the stone under magnification, the one that was visible is the one at 5 o’clock on the second drawing to the right on the GIA. The associate I was working with said the prong from the setting I chose could be used to cover it. She then adjusted the setting that she was using to show the diamond and in fact, I could not see the inclusion after she put the prong over it—even under magnification. Thoughts on that?

    I understand that I will pay more at a jeweler vs. james allen. I’m fine with that. But are super ideal cut diamonds worth it? The setting selection online is not sufficient for my girlfriend’s taste and even if i were to consider buying a loose stone, my experience seeing all the diamonds in person and side by side is something I am willing to pay a premium to be able to do. From doing some comparables in size, clarity and color to this stone from james allen, it appears that premium is somewhere around 10-15%, as this diamond was quoted at $31,630.

    With that said, is there anything you see in the GIA, or anything I’ve mentioned in this email that makes you believe this is not a stone I should purchase?

  8. Paul Gian-
    December 7, 2018 at 4:32 am

    This is an absolute disaster of a diamond that’s cut poorly. It is in no way, shape or form a super ideal cut diamond. The pavilion angles are too steep and they cause light leakage.

    Please read these links in full:

    I tell people to go online NOT because of better pricing (that’s just a by product). The most important factor is the diamond’s selection and cut quality you CAN find online and not the typical junk available in the market.

  9. Bob-
    December 10, 2018 at 9:45 pm

    I reread your article on round ideal proportions. I understand why the diamond they showed me is a bad buy.

    I applied your ideal round requirements on james allen and I couldn’t find a single one that met all specs (at least one that was 2.0 carats or higher and under $40K).

    The closest I came was the below stone. Note: It meets all criteria (I believe), except the pavilion angle is 41.1, not 40.6 – 41. I’m hoping the cut quality is good enough for the price point.

    Since the below stone does not meet your specs, do you have a different recommendation? Again, my budget is $35-$40K. Did I miss some that qualified? My head is spinning!

    Many thanks for saving me from a horrible purchase. I barely slept last night.

  10. Paul Gian-
    December 11, 2018 at 2:45 am

    This James Allen diamond is decently well cut:

    However, if you are looking for the best of the best in terms of sparkle and cut precision, these are 2 other diamonds that I would recommend if you want the best cut standards for a round brilliant cut diamond:

    Both stones are eyeclean and have the absolute best performance that a round diamond can be possibly cut to.

  11. Bob-
    December 12, 2018 at 1:45 am

    Thanks for the prompt response!

    I prefer the whiteflash one over the brian gavin diamond.

    That said, the difference between the allen diamond and the Whiteflash one is $2560. James Allen offers a “free” ring with the purchase of a $30K+ diamond so that makes an approximate $4-5K difference between the two. Do you feel there is enough value (not sure what other word to use) in the better stone to warrant the $4-$5K?

  12. Paul Gian-
    December 14, 2018 at 3:28 pm

    Honestly, I would say no. The extra costs will not be justifiable.

    The tangible data for this James Allen listing also points to it having great performance. It’s just that in terms of optical symmetry (hearts and arrows images) there are some very minor inconsistencies.

    James Allen is running a special promotion for this week and that’s the only time of the year they do “sales”. And given the amount of money you can save with James Allen, I would say, go with James Allen. On other days, without the sale running, I would gravitate towards the WF/BGD diamonds.

    Unless there is a specific setting (i.e. designer setting) that you can only get at White Flash / BGD, then it would make sense to fork up the money.

  13. Bob-
    December 18, 2018 at 2:50 pm

    I had to think for a couple of hours. Thanks for holding my hand through this process.

    The setting is where I’m torn. Let’s take the setting out of the equation, as I do want to customize it a bit and I find the ones on the online sites to be limited, for lack of a better word.

    If I’m going to take the stone to a jeweler to be set I want to make sure I am understanding you correctly—you much prefer the White Flash stone over the JA one even though it’s $3K more, right?

  14. Paul Gian-
    December 19, 2018 at 6:18 pm

    Yep. You are right. If money were no object, the WF option would be the better cut diamond if I am super anal. The other plus point is that it is slightly larger in carat size as well.

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