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Understanding The Diamond Culet: The Ultimate Guide

By Gary A.

Edited by Brian M.

Published Sep 18, 2021

Edited on Oct 15, 2024

A diamond’s brilliance is often judged from the top, but did you know that the diamond culet plays a subtle yet crucial role in its sparkle and appearance? Let’s explore why!

Navigate This Guide:

  • Introduction to Diamond Culets in Engagement Rings
  • 7 Practical Tips for Examining Diamond Culet When Buying an Engagement Ring 
  • The Anatomy of a Diamond Culet 
  • The Culet’s Role in Diamond Anatomy and Appearance
  • Understanding GIA Cut Grades and Culet
  • Choosing the Right Culet Size for Your Diamond Ring
  • Conclusion
  • 8 FAQs

Introduction to Diamond Culets in Engagement Rings

Before you started to learn about the ins and outs of diamonds – in fact before you even decided you were going to propose – you were probably familiar with the traditional profile of a round cut diamond.

And, while the terms ‘table’, ‘crown’, ‘girdle’ and ‘pavilion’ probably used to hold totally different meanings for you – and the term ‘culet’ would have meant absolutely nothing – chances are you were aware that this classic diamond shape features a long, tapering lower half that eventually ends with a sharp point.

Many of us start our journey fixating on the birds’ eye view of the diamond – the shape seen from above, whether it’s round, oval or something a little less common, like the heart. Nevertheless, every part of the diamond’s cut is vital to its overall appearance and, as it turns out, that traditional profile requires the same attention to detail as every other viewpoint – starting from the culet.

This is a vital consideration when determining the strength (or potential weaknesses) of a diamond’s proportions, and understanding it must be factored into your ‘To Do List’ before you visit our online store.

Before we dive deeper into the specifics, here are some practical tips to help guide your decision-making process:

7 Practical Tips for Examining Diamond Culet When Buying an Engagement Ring 

  • Tip 1: Understanding the Size of the Culet Check the Culet Size: Ensure the diamond’s culet size is appropriately small, ideally ‘None’ or ‘Very Small.’ A larger culet can be visible as a dark spot in the center of the diamond, affecting its overall appearance. 
  • Tip 2: Examining the Culet’s Impact on Brilliance Assess Light Performance: Observe the diamond under various lighting conditions. A well-cut diamond with a properly sized culet should exhibit maximum brilliance and sparkle, without any noticeable light leakage through the culet. 
  • Tip 3: Inspecting for Symmetry and Alignment Look for Symmetrical Culet: Check if the culet is centrally aligned with the diamond’s table. An off-center culet can disrupt the symmetry, affecting the diamond’s light refraction and overall beauty.
  • Tip 4: Evaluating the Culet in Different Diamond Shapes Consider Diamond Shape: Be aware that the significance of the culet can vary with different diamond shapes. For example, in antique diamond cuts like Old European or Old Mine, a visible culet is more common and can be part of their charm. 
  • Tip 5: Analyzing the Culet in the Diamond’s Setting Observe in Setting: If the diamond is already set in a ring, examine how the culet interacts with the setting. A protruding culet in certain settings can be more prone to chipping. 
  • Tip 6: Considering Culet’s Role in Overall Cut Quality Culet as Part of Cut Grade: Remember that the culet is just one aspect of the diamond’s overall cut quality. Evaluate it in conjunction with other factors like depth, table, and facet angles for a comprehensive understanding of the diamond’s quality. 
  • Tip 7: Comparing Diamonds Side-by-Side Side-by-Side Comparison: If possible, compare diamonds side-by-side to see how different culet sizes affect the overall look. This comparison can provide a practical perspective on how the culet impacts the diamond’s aesthetics.

Now that you’ve got these practical tips, use Jeweler AI below to find the perfect engagement ring that suits your style and budget:

The Anatomy of a Diamond Culet 

The culet is the lowest point on the diamond.

Pronounced ‘Queue-let’, the culet is generally characterized by a sharp, precise point where the long facets of the pavilion meet. In these instances, however, the point is often referred to as ‘no cutlet’ as, in some diamonds, the culet is turned into another small facet with a single cut that runs parallel to the diamond’s table.

This is why round cut diamonds can have either 57 or 58 facets. Those with 58 facets will have a cutlet that runs parallel to the table, while those with 57 will feature a sharp point

Many of us are so used to the traditional ‘diamond shape’ – and so caught up in the birds’ eye view of a diamond – that we don’t question why they feature this precise point at their base – or whether we want to find a diamond with or without one. Not only that, but the way the culet is cut plays a central role in the diamond’s overall appearance, and in its value.

Should a Diamond Have a Culet? 

These days, the culet is there to offer a little extra protection to the diamond between the time it is cut and the time it is mounted into jewelry, since a sharper point at the bottom of the pavilion is more liable to break than an additional, flat facet is.

Remember that this part of the diamond is still pretty strong, but that you wouldn’t want it to be subjected to a blow or hard knock. A diamond without a culet is just more vulnerable. 

However, provided the person setting the diamond within the ring (or any other item of jewelry) is careful, the risk to the diamond’s structural integrity is pretty low. This is why it’s preferable to shop from established and highly reputable stores, rather than the cheapest option, as you can be sure of the levels of skill, care, time, and attention that go into this delicate process.

Once set within a well-crafted ring setting, the culet is no longer anywhere near as vulnerable to damage.

This is why, for the most part, today’s diamond’s don’t generally feature culets. Shoppers are getting increasingly wise about where (and who) they shop from and are turning to trusted online sources where they know a  diamond is treated with the care it deserves

The Culet’s Role in Diamond Anatomy and Appearance

A culet is now considered a pretty negative feature for a diamond, since it Is visible through the center of the table and can appear as an inclusion in an otherwise eye clean diamond.

To be clear, a culet is not an inclusion or a blemish, so, for instance, a diamond with a large culet can still be graded VVS1. However, the culet will have a significant impact on your birds’ eye view of the diamond. 

Put simply, when a culet is cut into a diamond, then its own transparency can work against it since this additional facet will be visible through the table. As a result, the clean, crisp view through the center of the diamond is infringed upon, and, as we mentioned above, can appear included – even if you’re paying for eye cleanliness. In cases where the culet is particularly small, this may appear as a relatively minor black dot but, even then, it can be hard to see past when you’re hoping for visual perfection.

What’s more, adding another facet to the diamond can create its own problems…

The Impact of the Culet on Light Performance

In some cases the culet can be big enough to reduce a diamond’s light performance.

As we mentioned before, flattening the base of the pavilion means turning an otherwise sharp point into a brand new facet – and that naturally means that some light will be lost through it.

Losing light through the base of the diamond is certainly far from ideal. This is light that would otherwise be refracted back through the stone and transformed into additional sparkle on the diamond’s surface. That high degree of sparkle we all covet is caused by a complex path that light takes through the table, between the many facets of the pavilion (a process known as refraction) and back out through the table and crown of the diamond. Light lost through the base of the diamond is, unfortunately, light wasted.

Small culets are unlikely to cause a tangible drop in the diamond’s light performance, but they can still appear as dark spots, visible through the diamond’s table, and undermine the time and money you invested into finding an eye clean diamond.

Understanding GIA Cut Grades and Culet

The GIA grades the culet using percentages, calculated according to the ratio of the diamond’s average diameter to the measurement of the culet (if, of course, it has one).

Much like the GIA’s grades for table and depth, culet size grades are designated by percentage (specifically, the size of the culet divided by the average diameter of the diamond, multiplied by one hundred), rather than a particular size as, while a 1mm culet could be large for a smaller diamond, it would be considered very small on a diamond with a higher carat grade.

no culet vs noticeable culet
No culet (left) vs Noticeable culet (right)

Here are the following culet grades, as used by the GIA:

  • None – This is also known as a pointed culet, and simply means that the pavilion tapers off into a perfect point. The GIA regards this as an intrinsic part of an Excellent cut diamond.
  • Very Small – Comprising less than 1.5% of the diamond’s average diameter.
  • Small – Comprising around 1.5% of the diamond’s average diameter.

Up to this point, the culet can go unnoticed unless under intense magnification. The following grades are not so forgiving, and a visible culet will grow more noticeable with each grade:

  • Medium – Comprising around 3% of the diamond’s average diameter.
  • Slightly Large – Comprising around 5% of the diamond’s average diameter.
  • Large – Comprising around 7% of the diamond’s average diameter.
  • Very Large – comprising around 11% of the diamond’s average diameter.
  • Extremely Large – Comprising 15% or more of the diamond’s average diameter.

No culet (left) vs Noticeable culet (right)

Choosing the Right Culet Size for Your Diamond Ring

Having no culet at all is always the best option and, given the fact that many, many modern diamonds are cut without a culet, it’s not difficult to hold out for a stone without this potentially disruptive feature.

In your diamond’s GIA Report, a section entitled Diamond Proportions will feature a detailed diagram that details factors such as table percentage and depth. Look for a grade of ‘None’ written alongside the diagram’s culet, and you can feel confident knowing that this feature will not encroach upon the diamond’s otherwise eye clean appearance and excellent sparkle.

Conclusion

So, do you need to worry about the culet? Yes, but predominantly no. There are far more pressing things to think about, especially in light of the fact that most diamonds on the market today feature no culet.

It is important that you remain keenly aware of the fact that a culet can totally disrupt the clear, unincluded beauty of a diamond, and that, in many cases, they should be treated as dealbreakers. However, once you’ve double-checked the culet grade for any diamond that comes your way, you really don’t need to give it much more thought.

This is particularly true if you’re buying from a reputable online store, since, without a culet, the diamond is slightly more vulnerable to damage during the setting process. Once mounted in the ring, the absence of a culet won’t matter but, until that point, you want to be certain that your diamond is in the hands of people who care. 

8 FAQs

  • Q: What is a diamond culet? 
  • A: The diamond culet is the small point or facet at the base of a diamond’s pavilion where the facets converge. It’s either a sharp point (no culet) or a flat facet (visible culet). 
  • Q: How does the culet size affect a diamond’s appearance? 
  • A: The culet size can affect a diamond’s brilliance and clarity appearance. A large or visible culet might look like an inclusion from above, while a small or no culet enhances the diamond’s overall sparkle and brilliance. 
  • Q: What culet size should I choose for the best sparkle? 
  • A: Ideally, choose a diamond with a “None” or “Very Small” culet size for optimal brilliance. These sizes ensure maximum light reflection without visible interference through the diamond’s table. 
  • Q: Can a diamond’s culet be too large? 
  • A: Yes, a culet that is too large can detract from a diamond’s appearance, making it look like it has an inclusion or reducing its brilliance due to light leakage. 
  • Q: Does a diamond without a culet risk chipping more easily? 
  • A: A diamond without a culet (pointed culet) is slightly more vulnerable to chipping at the base, especially during setting, but this risk is minimal if handled by a skilled jeweler. 
  • Q: Are culets common in modern diamond cuts? 
  • A: Modern diamond cuts typically have small or no culets, as contemporary cutting techniques prioritize maximizing brilliance and reducing visible flaws. 
  • Q: How do I know if a diamond has a good culet size? 
  • A: Check the diamond’s grading report, such as one from the GIA, which will include the culet size. Look for grades like “None” or “Very Small” for the best quality. 
  • Q: Can I see the culet with the naked eye? 
  • A: In most cases, culets graded as “None” or “Very Small” are not visible to the naked eye. Larger culets might be visible, appearing as dark spots through the top of the diamond.

Navigate the nuances of diamond culets effortlessly with JewelerAI – ensure your choice shines with perfection!