Anatomy of a Diamond
Understanding Diamond Anatomy
Every facet of a diamond plays a role in how it captures and returns light. Use GIA's interactive tool below to explore each part of a polished diamond — from the table at its top to the culet at its point.
The Key Parts
Table — the large, flat facet on top. It acts as a window, allowing light to enter and reflect back to the eye.
Crown — the upper portion between the table and the girdle. Its angled facets disperse light into fire — the flashes of colour you see.
Girdle — the widest edge of the diamond, where the crown meets the pavilion. It defines the outline and is where a setting grips the stone.
Pavilion — the lower portion below the girdle. Its facets act as mirrors, reflecting light back up through the crown. Too deep or too shallow, and light leaks out.
Culet — the tiny facet (or point) at the very bottom. A small or absent culet is preferred, as a large one can be visible through the table.
Why Proportions Matter
Brilliance is a matter of geometry. When a diamond's proportions — table size, crown angle, pavilion depth — are within ideal ranges, light entering the stone is reflected internally and returned through the top. When they are not, light escapes through the sides or bottom, leaving the diamond looking dull.
Our standard: We select only Excellent and Very Good cut grades, where proportions, symmetry, and polish are graded to maximise brilliance. Learn more in our Diamond Quality (4Cs) guide.