Diamond Cut

Diamond cut
Photo: Sarawut795 / Adobe Stock
As we continue to venture through the four Cs of diamond quality assessment, we find cut. For many, this is a confusing one because they immediately think about shapes and sizes. In reality, the cut of a diamond has an entirely different meaning. Let’s take a look!

What is a Diamond Cut?

Cut has nothing to do with shape, but what does it mean? Ultimately, we’re looking at the interaction between the diamond and light. Let’s not forget, in order to get onto a ring, a diamond needs to be expertly fashioned. With cut grading, this assesses the ability of the diamond to interact with and return light. Therefore, all sorts of elements are considered including polish, proportions, and symmetry.

For the final stone to have both value and beauty, the workmanship of the specialist is essential. While carat contributes most to price, cut is perhaps the most difficult to assess and break down. As you may know, the GIA (Gemological Institute of America) is the most recognized institute for diamond grading and they prioritize Carat, Cut, Clarity, and Color – otherwise known as ‘the four Cs’.

When reviewing a diamond, they will assess proportions and other factors that impact the face-up appearance of the gem. With these proportions, they can ultimately discover how well the diamond interacts with light and how this allows for fire, brightness, and scintillation.

What is an Ideal Cut Diamond?

This is a phrase you might discover while shopping for diamond rings, and it describes a diamond that has been cut to ‘ideal’ proportions while also boasting strong symmetry and polish ratings. Used for brilliant, round, and princess cuts, it’s a rare cut and one that is able to reflect most of the light that enters. With this in mind, it’s held in high regard and is normally the yardstick against which all other diamond cuts are measured.

What Does ‘Brilliant Cut’ Mean?

On the other hand, a brilliant cut diamond is almost self-explanatory. It has exceptional brilliance, and this comes from the number of facets that have resulted from the cut. Today, even the most experienced and skilled craftsman have to work hard in order to get a brilliant cut. Typically, it will have a cone shape, and this means that most of the light that enters is returned through the very top.

Diamond Cut Scale

Now seen as the industry standard, we’re going to learn the different levels that exist between Excellent and Poor on the GIA scale.  What exactly does Poor mean? Should you avoid it at all costs?

  • Excellent (EX) – If a diamond has been graded as Excellent, it has excelled in all of the appropriate determinants. For example, it has maximum brilliance, fire, and reflects most light that enters. As a result, it rarely loses life and sparkles through every occasion.
  • Very Good (VG) – In this category, light is reflected properly, and this leads to fantastic brilliance and fire. Under the right lighting, it will look just like an Excellent cut. Unfortunately, the right lighting isn’t always available.
  • Good (G) – With a good amount of light returned, the appearance of this diamond is above average still. Compared to the higher two categories, these cuts are far more affordable while still boasting a strong appearance.
  • Fair (F) – Sadly, this is where we start to see some of the light escaping through the bottom or the sides. As a result, the brilliance and fire are somewhat reduced. Generally, this is acceptable when a diamond is less than 0.75 carats because it’s harder to notice the differences in sparkle.
  • Poor (P) – Finally, as you probably guessed, a Poor cut will have most of the light escaping through the bottom and sides (with very little returned). Even without years of experience with diamonds, it’s possible to notice a dull tinge to the gem.

If you’re looking for superior brilliance, this will come with either Excellent or Very Good cuts. For those who want to save some money, dropping to Good or even Fair is acceptable in many cases. Especially when you choose a fancy shape, you don’t need a high cut grade. It might not have the same brilliance and scintillation, but it will allow you to choose a bigger size for an affordable price.

Meanwhile, avoid Poor cuts completely – this is true even if you’re focusing mainly on size. Though your wallet will thank you, these diamonds tend to be just as the label suggests.. poor.


Now, you should know the definition of an ideal cut, a brilliant cut, and have a better understanding of the diamond cut scale that is accepted across the industry. Next, we’re going to learn all about clarity!