How to Evaluate Diamonds with an Idealscope?

Once you’ve dipped your toes in the sea of diamond knowledge, there’s no turning back to simply trusting what the jeweler says! More and more tools will be known to you. Although their names are unfamiliar to the mainstream, they’re very handy and can truly help you in choosing the right diamond.

Learn how to evaluate Idealscope images

The reality is, to the untrained eye, it’s challenging to tell a well-cut diamond from a poor cut. And given the outstanding lighting a brick and mortar store flashes its customers with, it’s not hard to notice why a diamond can suddenly turn dull upon exiting the store.

Adding Idealscope-reading in your skill set will help you critically choose or filter diamonds based on their visual performance, and in turn, end up with a super excellent gem! Now, this post is all about the Idealscope, but not just how to use it, but how to find the best diamond with it as well.

How the Idealscope Works

How the Idealscope Works


If you want to start out examining the light performance of a diamond, there’s no better place to start out than with an Idealscope image. It can tell you a lot about where the light is leaking and how much light a diamond will actually reflect back to you. And as we know, only a diamond a lot of the latter will be the one full of brilliance, fire, and scintillation.


“The ideal scope creates a structured light environment. When the diamond’s girdle is aligned with the bottom of the tube, light entering the crown from above and properly returning to the eye will appear red. Light escaping or ‘leaking’ out of the diamond’s pavilion appears white. Light that comes from the very highest angle will appear black and represents light that is obscured by the observer’s head.” – Whiteflash


You should always demand an Idealscope image before buying a diamond – whether you are buying in a brick-and-mortar store or online. Some jewelry stores have Idealscopes, but many don’t.

The same applies to online diamond vendors. Most of them are only dropshipping their diamonds and thus are not able to offer you such images. James Allen, Whiteflash, and Brian Gavin are one of the good ones that show Idealscope images before buying a diamond.

Interpreting Idealscope Images is Easy-Peasy

Red and Black:

Chessboard with dark contrasts appears brighter than a completely white area


Basically, there are only three colors you need to pay attention to. The red color signifies areas of light reflection which are highly desirable. You want your diamond to reflect a lot of light!

The dark color symbolizes the symmetrical and distinct dark contrasts in a diamond. You also want to have your diamond to have these contrasts because they will make your rock appear brighter.

That sounds counter-intuitive but see it as a chess board. It only has half the light return of a completely white board, but when you move it, it will appear livelier than the white one. This is due to the scintillation effect caused by contrast.

For this very reason, dark contrasts in diamond are always welcome. The strongest ones are provided in hearts and arrows diamonds which offer a strong opposing pattern.

Light Red:

Idealscope Lighter Red

The light red color in an Idealscope image symbolizes areas where the diamond is reflecting back less light. Every diamond has some areas of lighter red although, in super ideal cut diamonds, even these light red areas are harder to make out. So, the less you find it in an Idealscope image, the better the diamond’s overall light performance will be!

White/Clear Color:

Now, the white color symbolizes areas of light leakage. It is clear that you want to avoid diamonds with this kind of leak. They occur due to bad proportions which means that certain angles within the diamond are outside the perfect diamond proportions.

Ideal Scope Contrast Leakage – You will notice a small regular pattern of small white leakage around the perimeter of well-cut diamonds. This type of leakage is acceptable and contributes to positive contrast and scintillation. – Whiteflash

Light leakage in such cases might look something like this:

Diamond proportions influence an Idealscope image


Other than that, a diamond could also exhibit light leakage due to symmetry issues:

The diamond symmetry also impacts an Idealscope image

(Pictures are courtesy from

Many people think that the diamond cut and the diamond symmetry are exactly the same thing. However, they fail to realize that a diamond could be perfectly symmetrical, but for instance, have a very steep pavilion angle. This would result in a deep diamond with a terrible light performance:

A steep pavilion angle causes a deep diamond with lots of light leakage.


But actually, it does not matter so much whether you understand why a diamond leaks light. The most important thing you need to know is that it does leak light. And Idealscope images can help you a lot with that!

Let’s Practice Making an Idealscope Image Evaluation

Whiteflash diamonds Idealscope comparison

The diamond on the left is taken from Whiteflash’s A CUT ABOVE signature line – one of the worlds #1 cuts. The diamond on the right is from the Premium Select signature line.

I think that there’s no need to encircle the areas of white light in the right diamond. It’s pretty obvious that compared to the left one, the right diamond leaks more light.

In this case, it would obviously be the best decision to go with the diamond on the left. But let’s have a look at a more difficult example involving 3 diamonds. If you need to, you may click on the images for a better view:

Whiteflash Diamonds Idealscope Comparison

Entertained yet? This one is an extremely tough call to make! And indeed, if it wasn’t for one little extra feature that I wanted to show you in this example, I think I would have a difficult time choosing the best diamond, too!

Now, in all three diamonds, we cannot make out any white spots that would indicate light leakage. But we can see areas of lighter red relative to the darker red. So, let’s only pay attention to the lighter ones. Which diamond has the most? Correct! It’s the right diamond.

So, we only have the diamonds on the left and the middle. If we are to base our decision only on the spots with light red, it would be challenging. Although I would go for the diamond on the left because to me, it seems to have fewer spots of lighter red. But there’s also another reason to go for it:

Areas of light return are preferred to areas of light contrast in an Idealscope image

Look closely at the black color. In the diamond on the left, the contrasting color solely comes from the arrows in the diamond. As I have told you, contrast is good, but if you can have an area of light return instead, it is even better! This is due to the fact that you already have a nice contrast in the arrows anyway.

The diamond on the right, however, also displays minute areas of contrast apart from the arrows pattern. I have circled these areas in blue. This is very common, and you have nothing to worry about!

Although the contrasting pattern that didn’t come from the arrows isn’t symmetrical. You can clearly see it just looking at the blue circles. They are spread unevenly. In a case like this, the brightness effect through the contrast will be diminished, and it is wiser to go for more areas of light return.

Whiteflash A Cut Above

Please note that these are tiny differences that you would most likely not notice with your naked eye. Furthermore, the dark areas that I encircled can have a positive impact if they are evenly distributed. Still, if you are here to make the best choice, this is what you have to do.

The funny thing is that the diamond on the left is from the Expert Selection and not from Whiteflash’s A CUT ABOVE signature line. So, the diamond on the left didn’t make it into the A CUT ABOVE signature line because it doesn’t possess the best polish grade.

In reality, though, you will most likely never see a difference between the best and second best. You can read more about that in my post about diamond polish. I know that such Idealscope analyses can be quite tricky sometimes!

The Takeaway

Ain’t that quick and easy? This goes to show that we shouldn’t be alarmed with unfamiliar images that may seem complex. With the right understanding and handy tools, you can evaluate your own diamond’s light performance and potentially own the best one right up in your budget. 🙂

Should you have any questions, feel free to leave a comment or drop me a mail!

My advice is free. 🙂