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Diamond Diagram - Diamond Structure 

Our diamond diagram is a diamond structure diagram of a round brilliant-cut diamond. Based on a modern brilliant cut, the diagram includes all key parts of a diamond. Polished diamonds result from an evolution of cutting and polishing. Most polished diamonds feature common elements, named in our diagram below. You will note that there are two main divisions on our diamond diagram—the Crown and Girdle. Below our diagram, we have included a list of the key parts of a diamond as shown on the diagram below. 

Key features of the diamond diagram


Refers to the upper half of the diamond. Separated from the Pavilion by the diamond Girdle. 


Diameter represents the measurement across the stone from girdle to girdle. The maximum and minimum diameter of a round brilliant cut diamond appears on a diamond grading certificate. For example, a half carat diamond may measure 5.05-5.08mm in diameter at different points across the stone. 


Refers to the top facet of the diamond. The table size is shown on a certificate as a percentage. Old cut diamonds differ from modern cuts in table size. Modern diamonds tend to have larger Tables, allowing light into the diamond. The Table facet appears at the very top of our diamond diagram. 

Kite Facet - Star Facet - Upper Girdle Facet

Kite facets and Star facets get their name from their shape. Appearing around the diamond, diamond facets provide scintillation as light dances from facet to facet, reflected back to the observer. Along with the upper girdle facets they appear in the upper Crown of the diamond. 

Diamond Girdle 

The Girdle of a diamond runs around the edge of the stone. Diamond girdles are either polished or bruted. Most GIA certified diamonds feature a microscopic diamond certificate number lasered onto the edge of the diamond. Our blog features a dedicated article on reading this inscription using a dedicated instrument. 


A diamond Pavilion is the lower section of the diamond which carries most of the depth of the stone. 

Lower Girdle Facet - Pavilion Facet

The lower girdle facets encircle the lower part of the diamond. Pavilion facets descend to the point or Culet of the diamond. 


A diamond Culet is the bottom tip of the diamond. Old cut diamonds often feature a polished flat Culet. This appears as a small circular shape when viewed through the table Facet. Damage to the Culet will be visible through the table facet.

Additional Parts of a Diamond

Diamond diagrams can be far more technical depending on the level of detail they include. Our diagram represents the basic Anatomy of a diamond, detailing the key parts of a diamond including Facet names.