23 Key Diamond Grading Questions

Diamond Grading QuestionsSo, you are at your local jewelry store and you want to make sure to choose the best diamond?

Then ask and you shall receive!

By asking yourself the following diamond grading questions you will make absolutely sure that you make a great deal!

If you are shopping online at vendors like James Allen you can view ALL the diamonds in high definition 360º videos. You will thus be able to apply most of these questions to diamond online shopping, too!

Here is my list of the 23 Key Diamond Grading Questions:

1. May I see the diamond grading report for this diamond?

This is a crucial question because if you really want to have a high quality diamond it has to be graded by either GIA or AGS. These are the top two diamond grading labs with the most consistent and reliable results.

Typical GIA grading report

Other grading labs tend to grade diamonds 1 or 2 grades higher than GIA or AGS would. This way, you end up paying more. And in fact, this is a method that is used by jewellers all over the world to get you to pay more.

Read more about this issue on my post about the best grading labs.

2. The diamond we are looking at is a “G” color. Can I see a diamond next to it that has an “F” color or “H” color so I can see the difference?

That is important to do so that you can get a proper feeling for the diamond color. Maybe you find out that you don’t see any difference between the single color grades. That might be a good opportunity to lower the color grade to get an even better bang for your buck.

        • F-colored diamond
        • G colored diamond
        • H colored diamond

Make sure that all diamonds have diamond grading reports by AGS or GIA!

3. Can we view the diamonds on a white paper so we can properly judge for color?

Viewing the diamond on white paper will enable you to see the real body color of the diamond best. It is much easier to differentiate between several diamonds when viewing them on a white background!

4. Can you see any flaws from the top of the diamond with the unaided eye?

You have to look very closely at the diamond. If you cannot see any flaw by looking very closely at the diamond, it is likely that nobody will be able to make out any flaw!

5. Can you see any flaws from the bottom of the diamond with the unaided eye?

And you also want to make sure that you cannot see any inclusion from the bottom of the diamond. Only then can your diamond be really considered eye clean!

6. I would like to see the diamond in the following different light sources:

  • Incandescent Light
  • Fluorescent Light
  • Direct Sun Light
  • Indirect Sun Light
  • Special Diamond Light

This will allow you to truly understand the diamond’s light performance in different lighting conditions

7. What are the crown angles, pavilion angles, table percentage and depth?

You don’t just want to have a look at the diamond but you also want to know the diamond’s exact proportions.

Diamond Proportions

Why should you do that?

Simply to make a really educated decision! It’s exactly these kind of proportions that will determine the light performance of a diamond!

8. Are the percentages within the acceptable ranges?

Only looking at the diamond proportions without knowing which are good will not help you a whole lot though.

Read my post on the round cut diamond to discover the acceptable ranges and also the high-end ranges for super ideal cut diamonds!

Going for a super ideal cut diamond will maximize the light return and thus the brilliance and scintillation of a diamond.

9. What does the girdle look like? Is it polished?

There are three types of diamond girdles: Faceted, polished and bruted.

You either want to go for a faceted or a polished girdle. A bruted girdle is a girdle in its original form which means that the girdle has not been touched with the polishing wheel at all. It does not look good and should definitely be avoided.

10. Does the diamond have fluorescence? If so does it give a milky effect or is it a very clear diamond?

Some diamonds exhibit fluorescence which means that they fluoresce in blue color if they are subjected to a UV light source.


The good news is that fluorescent diamonds are cheaper but the bad news is that some fluorescent diamonds have a milky look to themselves.

This is why it is so crucial to have a very close look at fluorescent diamonds!

Read more in my post about fluorescent diamonds.

11. What is the cut grade?

The diamond cut is the most crucial 4C parameter. If you want your diamond to display the highest amount of brilliance, sparkle and scintillation you should make no compromises and always choose the best cut grade!

12. What is the polish grade?

The polish grade does not necessarily have to be the best. The second best polish grade will do just as well!

I was never able to notice the tiniest difference between an “Excellent” and “Very Good” cut grade with my bare eyes. And I don’t know anyone who would be able to notice.

13. What is the symmetry grade?

Contrary to popular belief the diamond symmetry does not affect the diamond’s light performance as much as the diamond cut does!

The reason is simply the fact that it is the exact crown angles and pavilion angles that mostly determine in what kind of way and in what amounts the light is reflected back to the viewer!

A diamond’s symmetry can be slightly off but the crown angles and pavilion angles can still be perfect. And with it the light performance of a diamond.

Thus, a “Very Good” symmetry grade would not necessarily be a reason to discard a diamond.

14. What is the clarity grade?

Here, you just want to have the awareness that any clarity grade above VS2 basically comes down to overpaying on a premium feature.

Virtually all VS2 diamonds graded by GIA or AGS are eye clean and this is the only thing you should be concerned about!

If you want to get an even better bang for your buck try an SI1 diamond. Some of them are eye clean and some of them are not. If you buy at a vendor like James Allen with up to 40x magnification you will easily be able to pick an eye clean SI1 diamond:

Comparison between an eye-clean and a not eye-clean SI1 diamond

Going better than a VS2 clarity grade will only cost you more and look just the same to the naked eye!

15. What is the carat weight?

Avoid diamonds that are exactly within cut off weights such as 1.00ct – 1.01ct, 1.50ct – 1.51ct or 2.00ct – 2.01ct!

For one thing diamonds tend to rise very sharply at these weight points.

Furthermore, in case your diamond should ever chip (which rarely happens) the repolishing will reduce the weight below the magic 1.00ct, 1.50ct or 2.00ct mark. This will put your diamond into a lower price category which you want to avoid!

16. How old is the date on the diamond grading report?

You don’t want your grading report to be too old! It is ideal if your grading report is no older than 3 years.

Grading standards change regularly and you want your grading report to reflect the latest developments.

17. Is the diamond laser inscribed?

If your diamond is laser inscribed you will find this information on the grading report in the section “additional grading information” under “inscriptions”.

The most usual laser inscription you will find is the grading report number inscribed on the diamond girdle. This is a great way to be absolutely sure that you really received the diamond that the grading report is all about.

AGS diamond laser inscripton on the girdle

By the way, diamond laser inscriptions are so tiny that you won`t be able to make them out with your bare eyes.

18. Do you consider this a good or bad VS2 clarity grade?

In very rare cases a VS2 diamond can be not entirely eye clean. It hardly ever happens but it is always good to make sure the eye cleanliness yourself.

Additionally, it is always good to ask a professional jeweler or gemologist for a second opinion because some people have better eyes than other people.

19. Is this the original diamond grading report?

The original diamond grading report has a much greater value than a copy of that grading report. You should always make sure to get the original grading report.

Typically, if you lose your grading report getting a new original grading report from GIA can cost you around $100!

20. Is this diamond in the same condition as stated in the diamond grading report?

Make sure that the diamond still has the same carat weight and check the diamond for chips and scratches.

You don’t want to pay for a diamond that has worse characteristics than laid out in the grading report!

21. What do the entries under “Key to Symbols” mean?

Typically in diamonds above 1 carat you will find clarity plots with all the inclusion types of a diamond on the grading report.

Complete list of diamond inclusion types in GIA a plotting diagram

There you will find different inclusion types like featers, needles, twinning wisps etc. You want to make sure that you actually understand the meaning of all the different inclusions.

If you want to know more about specific inclusions please read my post on the different diamond inclusion types.

22. Does the plotting of the flaws on the diamond grading report match what you see under the diamond loupe?

Just to make sure once again that you are really viewing the diamond that is indicated on the grading report: Try to see whether you can make out the inclusions that are depicted on the clarity plot!

23. Does the diamond have brilliance and scintillation?

Diamonds exhibit both brilliance and scintillation.

Brilliance refers to the the white light that is reflected by the diamond and the scintillation refers to the rainbow color light that is reflected.

The best diamonds have a large amount of both brilliance and scintillation and you want to make sure that your diamond is just like that.


Asking all of these key diamond grading questions will ensure that you truly understand what kind of diamond you are getting. You could not possibly make a more educated decision than that!

If you really want to get a great bang for your buck it is always more advisable to shop online because diamond online vendors have much lower operating costs.

However, with most online diamond vendors you are buying the diamond blindly which is never a good idea!

This is why I recommend to check out James Allen where you can view all diamonds in up to 40x magnification(!) in high definition 360° videos.

James Allen 360° Display Technology

Go and check out James Allen’s 360° Display Technology now to make the most educated diamond buying decision!

If you have any more questions on diamond grading just leave me a comment or drop me a mail! I will be more than glad to help you out!