suite of different diamond cuts Knowledge is power, and it certainly applies to the process of choosing a diamond. Good knowledge and research would help diminish the element of uncertainty in an expensive purchase.

Admittedly, sometimes there can be things that may be out of your control. For example, if you have a $3000 budget and are looking for an F color cushion, you might not be able to find a suitable diamond in stock and may have to settle for a G color diamond instead.

At the end of the day, you would need to explore your preferences and options by being clear on what you want. By doing your research at the forefront, it would enable you to make good decisions and avoid “after-sales remorse”.

In a Hurry? Use This Checklist to Help You Choose a Diamond

Here’s a quick checklist to recap the steps to choosing a well-cut diamond (only applicable to round brilliant diamonds). It’s the quickest way to filter out poorly cut diamonds and narrow down your selections:

Weed out stones that fall outside the following criteria:

– Check for Table percentage to be within 54.0% – 57.0%
– Check for Depth percentage to be 61.0% – 62.5%.
– Check whether Pavilion Angle is within 40.6° – 41.0° range.
– Check whether Crown Angle is within 34.0° – 35.0° range.


– Filter down your choices to GIA Excellent Cut or AGS Ideal Cut.

Like I mentioned earlier, this is just a quick guideline to help you increase the probabilities of getting a great looking stone. On rare occasions, a diamond with a cut grade of Very Good can actually have better optical properties than another stone graded with Excellent or Ideal cut.


Calculate the HCA score! Reject any stones with scores higher than 2.0.
Verify the optical performance with Idealscope/ASET data.

This checklist is designed based on even more stringent cut proportion guidelines than those set by GIA & AGS.

With that said, regardless of whether you are buying online or in stores, I can assure you that you will end up with a beautiful diamond if all these criteria are checked.

Once ready, I recommend starting your search at White Flash and James Allen. Not only will you enjoy lower prices, you also get a significantly better selection of diamonds to pick from.

A Final Closing Note

ring balancing on rocks

  • Diamonds are significant purchases. Do take your time to read and do your own research. There is a wealth of knowledge that you can pick up from the articles on

    If you have any questions that you can’t find answers to, or need to seek my opinion on any questions, feel free to contact me directly at paul [@]

    I would love to hear from readers and would be pleased to extend my help to you in a timely manner. Cheers!

    Paul Gian



    – End –

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    1. Gabrielle J.-
      June 13, 2013 at 3:06 am

      You stated that a diamond graded as a Very Good cut can actually look better than another with Excellent cut. How can this be? If I had understand correctly how GIA assign grades, they actually use observational techniques as part of the process. This means that the graders observe the stone before coming to a conclusion.

    2. Paul Gian-
      June 14, 2013 at 5:12 am

      Gabrielle, you are right. However, observation is just a part of the grading process. The cut grade is also affected by proportions as well as craftsmanship (finish) of the diamond.

      Let me quote an example. If a diamond had been cut to super ideal proportions and excellent symmetry. Everything is perfect except that the polish has a rating of Good. Overall, the cut grade would be assigned as a Very Good rating because the stone is penalized for the polish rating. However, the light performance can still be excellent and outperform triple excellent stones in this regard.

    3. Tan-
      November 3, 2014 at 12:14 pm

      Hi Paul,

      How about those diamond with higher facet? For example Brilliant Rose or Heart Of Fire? They don’t have prefect H&A but the price is steeper than normal triple excellent GIA or AGS diamond. Are these diamond worth the price?

    4. Paul Gian-
      November 3, 2014 at 1:13 pm


      Brilliant Rose diamonds aren’t that consistent in their cut quality. Most are OK but not great. More importantly, you really need to compare diamonds to make sure you don’t end up with crappy selections.

      Hearts on Fire is a brand that has much better cut quality and consistency. I actually wrote a review about them here:

      If you asked me, Hearts On Fire is the only international brand that I would consider paying a premium for. However, it still isn’t worth it because there are many other options that can provide better quality at lower prices.


    5. Raymond Lee-
      October 1, 2015 at 8:28 pm

      Nice write up. Thank you for all your great insight.

    6. Ross-
      February 29, 2016 at 7:28 pm

      Thanks for the great read. Definitely don’t know it all, but I realize now how much research I have yet to do.

    7. Sara-
      May 14, 2016 at 5:57 pm

      Hi Paul, I’ve been thinking to buy this diamond :

      Could you please advice me about this diamond?

    8. Paul Gian-
      May 15, 2016 at 6:43 am

      Terrible diamond. Absolutely a disaster in cut quality.

    9. Peter-
      May 16, 2016 at 8:46 pm

      Hi Paul,

      I enjoy reading your articles.

      You say a lot about cut and carat being most important. However, is there an optimal point to be at with a given price range. I know you can’t know for sure, but I am just looking for a general grid. I have a budget of $2000 to $3500 for a diamond and I am not sure what would be ideal combination.

      $1000 0.5 carat Excellent Cut K Color VS1 Clarity
      $2000 ?????? ??????
      $3000 ??????? ????

    10. Paul Gian-
      May 17, 2016 at 3:29 am

      Nope. There isn’t. At the end of the day, color/clarity/carat combinations are purely personal preferences. Just know that CUT is KING and everything follows after.

    11. Yang Kin-
      May 19, 2016 at 12:31 am

      Hi Paul,

      Great website!

      I would like to ask if Lazare diamonds are any good?

      All their diamonds are cut within their ideal-cut specification:

      Table percentage is within 53.0% – 57.4%.
      Depth percentage is within 59.7% – 62.3%.
      Pavilion Angle is within 40.7° – 41.2° range.
      Pavilion Depth percentage is within 42.7% – 43.8%.
      Crown Angle is within 33.7° – 35.5° range.
      Crown percentage is within 14.8% – 16%.

      Thank you in advance.

    12. Paul Gian-
      May 20, 2016 at 1:28 am

      If you go study diamonds in a little more detail, you will realize that those dimensions DO NOT always give rise to well cut diamonds.

    13. July 23, 2016 at 2:10 pm

      Hi Paul – great website!! Very informative, it’s helped my cull my list from 12 down to 3!!
      I have started my research and I have narrowed it down to some possibilities I would like your opinion on, trying to get best value for money (trying to keep under S$5000) so of course the best of all world required – All “C’s” as best/large as possible haha! I am from Australia so also looking there to to see if i can ship there then have a friend bring for me if it saves on import..


    14. Paul Gian-
      July 23, 2016 at 4:21 pm

      Of the lot, the first diamond is the most promising. It appears to be very well cut.

    15. Jay S-
      August 4, 2016 at 5:59 pm

      Thank you for your detailed website. I followed your specific advice and ended up with a diamond ring (from WhiteFlash) that my fiancee loves!

    16. Michael-
      August 8, 2016 at 3:01 pm

      Hello Paul,

      I have been looking at diamonds, and I was considering this. Please tell me what you think.

      Thank you for your time and opinion.


    17. Paul Gian-
      August 9, 2016 at 9:45 am

      Proportions wise, it looks like a good stone but that isn’t sufficient to make an educated decision on a purchase.

    18. Belinda-
      August 16, 2016 at 3:00 pm

      Dear Paul,

      I stumbled upon your website trying to find some information to read after I bought this ring for around $1.6k (I bought at SGD2,151).

      The ring is set in an 18k white gold.

      Would be interested to know your thoughts on whether I bought it at a good price. This is the first time I bought a diamond for myself sort of an early birthday gift. However, since you mentioned that cut should at least have an excellent rating, I am thinking that this may not be a wise purchase at all.

      Lastly, thank you so much for putting together this very informative website.


    19. Paul Gian-
      August 17, 2016 at 1:36 pm

      You are right. The diamond isn’t that well cut. Try and see if you can get it traded up for another diamond but as far as I know, most Singaporean retailers do not offer good policies unlike the States.

    20. Andrew-
      August 17, 2016 at 6:42 pm


      First off, thanks for creating such a thorough guide. It’s made the process a LOT easier. Would you mind looking at these three and comparing them? The first isn’t available for inspection.

      Thanks in advance!

    21. Paul Gian-
      August 18, 2016 at 5:22 am

      Out of the 3 diamonds, only the first barely makes my standards to be purchase worthy. I did a search for you and would recommend these diamonds instead:

      They offer better value for money and are well cut!

    22. Paul H-
      August 21, 2016 at 12:38 am

      Hi Paul,

      I found your article very interesting and a lot more informative than all of the other things I have read. I have put 2 links below for diamonds which both fit within your recommended criteria. There is however a reasonable price difference between them. Would you be able to help me understand why and whether or not you would recommend buying one of them over the other or if I should look elsewhere?

      Thank you!

    23. Paul Gian-
      August 21, 2016 at 1:05 pm

      I’ve reviewed both diamonds here:

      On paper both diamonds look good but it is good to get images of both stones to make a better decision on choosing the better stone.

    24. Andy-
      August 23, 2016 at 6:58 pm

      Hi Paul,

      Thank you for putting together a series of articles on diamond education. For beginners like myself, this has helped me greatly on the selection process.

      I have narrowed down to this diamond below and would love to hear your comments on it. The image from the link has the actual diamond magnified.

      Thank you kindly!


    25. Melissa-
      August 31, 2016 at 2:08 am

      Paul, I found your article to be so informative. I spoke with a jeweler today who told me I may be better off with a spread cut diamond. I’m interested in a oval 2.2+ ct. What is the quality and cut of this diamond in your opinion? If I understood your article correctly this diamond will appear larger than it is? Would you consider this a good buy?


    26. Ben-
      September 28, 2016 at 12:43 am

      Hi Paul,

      Thanks for putting this website together. I poured over everything you wrote for hours. I think i’m ready to pull the trigger. I went to the store today and the jeweler spent a lot of time going over various diamonds with me. I think I have my eyes set on this one:

      can you give me your opinion? She said it was a very good cut. All of the percentages fall into the minimum thresholds you described.


    27. Paul Gian-
      September 28, 2016 at 1:19 am

      Terrible choice. Anyone who has the slightest knowledge about cut grading will tell you to avoid the diamond. The steep pavilion angle is 100% guarantee to cause significant light leakage under the table. That jeweler doesn’t has your interest at heart and just wants to close a sale at your expense. RUN.

    28. Ben-
      September 29, 2016 at 10:52 pm

      Hi Paul,

      Are you referring to the diamond i linked?

      All of the cut measurements fit your criteria, with the exception of the pavilion angle being 41.4 degrees, slightly outside the range of 40.6 to 41.0 degrees. Does 0.4 degrees make a big difference?

      if you are referring to my diamond, thank you so much for your advice. I was planning on going back to the store within a week to buy the stone, but will have to seriously reconsider it if you think this is a terrible choice.

    29. Paul Gian-
      September 30, 2016 at 2:12 am

      Yes. It’s a terrible diamond. Just a 0.2 degree offset is sufficient to cause serious light leakage.

    30. Steven-
      October 17, 2016 at 1:56 pm

      Hi Paul, thanks for your website, it provides a very useful guide for diamond purchasers. Can you please let me know your thoughts on this diamond? The depth is 62.7% and the crown angle is 35.5% but otherwise it meets the criteria.


    31. Steven-
      October 18, 2016 at 1:15 am

      Hi Paul, excellent website! Can you please let me know your thoughts on the following diamond:

      Is the depth 62.7% a concern (it is slightly outside the 61-62.5% range)?

      Thank you kindly!

    32. Paul Gian-
      October 18, 2016 at 3:52 pm

      Dump this diamond and look for another. There is no lack of better diamonds out there with better proportions. Why settle for this mediocre stone?

    33. Charles-
      October 20, 2016 at 2:37 pm

      Hey Paul,

      What do you think about this diamond for my fiance’s engagement ring. Any help would be appreciated. I,m looking for a diamond .7 or higher around 2000.


    34. Charles-
      October 20, 2016 at 2:37 pm

      Hey Paul,

      What do you think about this diamond for my fiance’s engagement ring. Any help would be appreciated. I’m looking for a diamond .7 or higher around 2000.


    35. Paul Gian-
      October 20, 2016 at 11:45 pm

      I can’t see details of the ring composition. You will need to paste the url link separately.

    36. Tracy Zhang-
      November 30, 2016 at 6:32 am

      Hi Paul,
      Thank you for these wonderful posts.
      I am looking at this diamond:
      Since they provide the actual picture, it seems like the strong fluoresce is not an issue. However, the cut is kind of out of the selection range, HCA seems acceptable.
      Do you have any suggestions?
      Thank you,

    37. Paul Gian-
      December 1, 2016 at 2:54 am

      It’s a terrible diamond choice. Cut quality is bad.

      I did a search for you and would recommend this instead:

      It’s a much much better choice than the lousy stone you picked.

    38. Tom-
      January 17, 2017 at 11:58 am

      Hi Paul

      Thank you for the very informative website.

      I am considering this diamond which satisfies all 4 criteria on your checklist:

      I plan to match it with this setting:

      I am ok with the colour – although rated H, it looks pretty colourless to me, and it will also be in a platinum setting.

      I am also ok with the obvious inclusion which is visible in the magnified picture (despite being VS2), as I don’t believe it will be noticeable without magnification.


    39. Paul Gian-
      January 18, 2017 at 10:12 am

      Tom, you are right about the diamond’s inclusion. The diamond is definitely eyeclean and the blown up view looks more scary than it really is. Go for the diamond! It’s a great choice.

    40. Nate-
      March 2, 2017 at 8:38 pm

      Paul – considering these below stones for these requirements: 1ct, Excellent, J, VS2. Around my budget, they all seem to have fluorescence…hoping that won’t be an issue. Any of these seem like decent stones?




    41. Paul Gian-
      March 3, 2017 at 4:43 am

      All 3 are mediocre diamonds. Dump them all and read this:

    42. Paul Gian-
      April 27, 2017 at 3:50 pm

      Annette, I would actually recommend picking your own diamonds for the earrings instead of using the presets. I would recommend this pair instead:
      These are cut for light performance and offer good value for money (hits a half carat size).

    43. Ryan S-
      May 9, 2017 at 4:29 pm

      Great site!!

      I had a question about this page. You mention go with Excellent+ or those specific ranges for Table, Depth, etc. What if a diamond is rated Ideal but has percentages outside of your range??

    44. Paul Gian-
      May 9, 2017 at 5:02 pm

      Dump it. Why even consider it when there are literally hundreds of better cut diamonds out there.

    45. Abe-
      June 24, 2017 at 3:24 am

      Just a quick comment to say your website is amazing. Thank you very much and incredibly helpful!

    46. Joel-
      December 20, 2017 at 4:39 am

      Hi Paul

      Firstly, thank you so very much for sharing your knowledge on diamond. I definitely learnt a lot. And it has helped me see through a lot of the salesman’s gimmicks and allow me to look for better diamonds.

      I would like your opinion on a ring I am trying to buy.

      A few issues:
      1. Based on your proportions, this diamond only has the crow angle slightly out. How strict would you be with your diamensions (because I seldom see diamonds that fit all the criterias)?
      2. I am a little concerned with the number of feathers and a crystal quite near the centre of the face of the diamond. Do you think I am right to worry or am I just being paranoid?
      3. This is a diamond from H&W, and their policy is that all VS2 diamond would need to be ordered (hence down-payment), thus the only thing I can see is this GIA report (without 10X and ASET scope imaging), so I am a little worried.

      Can you please let me know your opinion?

      Thank you.

      Kind regards

    47. Paul Gian-
      December 20, 2017 at 6:34 am

      The crown angles are too high and will cause an instant rejection if I were shopping for a diamond myself. And read this:

      You seldom see diamonds that fit those proportions and the reason why is what I had been mentioning all along. The huge majority of the diamonds in the market are cut to junk quality and barely passable standards by my account.

      And read this:

    48. Joel-
      December 21, 2017 at 6:30 am

      Hi Paul, thank you very much for your feedback. I have a few follow-up questions:

      1. I took your advice and disregarded the previous diamond. I have however found another one.
      This stone fits your criteria completely, so what are your opinions?

      2. As mentioned previously, H&W wants me to put down a deposit first. I have read your article on buying diamonds blind. But given all the criterias (and the fact that there seem to be very minor cloud in the diamond), do you think I should put down a deposit on this one?

      3. A more technical questions. I understand that you said that all the criterias (angles, etc) would allow that diamond to give proper light reflections, etc. But for a diamond that fit all your criterias, would there still be light leakage? i.e. is there still a big need to get an ASET scope to look at the diamond?

      Kind regards

    49. Paul Gian-
      December 21, 2017 at 8:10 am

      If you had read the article, the red flag of placing a deposit down should be extremely clear. Why do you need someone to shop blindly on your behalf with you taking on ALL THE RISK? Why are you doing business with mediocre business practices?

    50. Fernando-
      January 8, 2018 at 6:28 pm

      Paul, I cannot thank you enough for this incredibly valuable blog! I was able to find a very high quality diamond for half the cost of other diamonds with similar “paper specs”. The custom jeweler that is making my ring was utterly impressed by my find. Thanks again!

    51. Tim-
      March 31, 2018 at 5:47 pm

      Just wanted to clarify…when you say within, for example, the table percentage should be within 54.0% to 57.0%…does that include 54.0% and 57.0%? Or does that exclude meaning 54.1% to 56.9%?


    52. Paul Gian-
      April 1, 2018 at 5:45 am

      That includes 54.0% and 57.0%.

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