What Is the Diamond Culet?
The culet is the very bottom tip of a diamond, located at the base of the pavilion. In some diamonds, this point remains sharp. In others, it is polished into a very small facet that sits parallel to the table. At Joseph Jewelry, we consider the culet a small but relevant part of the diamond's overall cut structure.
In most modern diamonds, the culet is either absent or so small that it is not visible without magnification. Even so, it can affect how the diamond is graded and, in some cases, how it performs visually.
What the Culet Does
The culet exists to protect the very tip of the diamond. A sharp point at the bottom of the stone can be more vulnerable to minor damage during cutting or handling, so some diamonds are finished with a small culet facet instead of a pointed tip.
At Joseph Jewelry, we view the culet as a technical detail rather than a major visual feature. In most well-cut diamonds, it does not draw attention to itself.
How the Culet Is Graded
Culet size is typically evaluated as part of the diamond's overall cut assessment. Independent grading laboratories describe it using terms such as None, Very Small, Small, Medium, Slightly Large, Large, or Very Large. The grade reflects how noticeable the culet is when the stone is examined under standardized conditions.
This information is usually listed on a grading report along with other finishing and proportion details.
How Culet Size Affects Appearance
If the culet is none, very small, or small, it is usually not visible to the unaided eye and generally does not have a negative effect on appearance. In many diamonds, this is the preferred range because it preserves the visual integrity of the stone while still allowing for careful finishing.
If the culet becomes too large, it may be visible through the table as a small circle or opening at the center of the diamond. This can interrupt the pattern of light return and make the stone appear less lively.
How the Culet Affects Performance
A large culet can allow light to escape through the bottom of the diamond instead of returning it to the eye. When that happens, the diamond may show a visible area of reduced brightness in the center. This is one reason why oversized culets are generally less desirable in modern diamond cutting.
At Joseph Jewelry, we recommend paying attention to culet size as part of the broader cut evaluation, especially when reviewing older cuts or diamonds with unusual facet structures.
How the Culet Affects Value
In most cases, a culet that falls within the smaller grading ranges has little or no negative effect on value. A medium or larger culet may reduce desirability if it becomes visible or interferes with light performance. As with other cut details, the impact depends on how noticeable the feature is in the finished diamond.
The important question is whether the culet affects what you actually see when the diamond is worn and viewed in normal light.
A Small Detail That Still Matters
At Joseph Jewelry, we treat the culet as one of many details that contribute to cut quality. It is rarely the first factor that determines whether a diamond is attractive, but it should still be evaluated as part of the complete picture. A well-chosen diamond should be balanced in its proportions, strong in light performance, and free from avoidable visual distractions, including an oversized culet.