Culet
The culet is the small facet or point at the very bottom of a diamond, where the pavilion facets meet.
The culet is the very bottom of a cut diamond, the point where the pavilion facets come together. It can be a true point or a tiny extra facet. GIA grades its size from none, meaning a point, up to extremely large, and on a modern diamond you generally want it to be none or very small.
Culet size and how it is graded
GIA grades the culet as none, very small, small, medium, slightly large, large, very large and extremely large. On most modern round brilliants the pavilion facets meet in a point, graded none, or the culet is very small. A larger culet is a flat facet at the base, which was common on older cuts but is usually avoided today.
The reason to keep it small is what you see from the top. A large culet appears through the table as a small dark or open circle at the centre of the diamond, a bit like looking down a tiny hole, which distracts from the stone's appearance. A pointed or very small culet is invisible face-up.
- Graded from none (pointed) to extremely large
- Most modern diamonds are none or very small
- A large culet shows as a dark spot through the table
- A very small or absent culet is ideal
The culet and durability
A true point can be slightly more prone to chipping at the tip, which is one reason some diamonds have a very small culet facet to protect the base. On old cuts a larger culet was partly practical, protecting the point before modern setting techniques. Either way, GIA notes the culet size on the report and folds it into the cut assessment, so an extremely large culet counts against the grade.
- The culet is the point or small facet at the base of a diamond.
- GIA grades it from none, pointed, to extremely large.
- Most modern diamonds have a none or very small culet.
- A large culet shows as a dark spot through the table.
- Culet size is noted on the report and affects the cut assessment.
Culet, in short.
What is the ideal culet size?
None, meaning the pavilion facets meet in a point, or very small. Both are invisible from the top. A larger culet can appear as a dark spot through the table and is usually avoided.
Why does my diamond look like it has a hole in the middle?
That is likely a large culet seen through the table. On older or poorly cut stones the flat culet facet shows as a small dark or open circle at the centre. Modern well cut diamonds avoid this.
Related terms
See culet inside a real jewellery system.
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