Diamond anatomy and the impact of light

Diamond anatomy can be broken down as follows:

Crown – The crown is situated between the girdle and the table; it is the top part of a diamond.
Culet – The culet refers to the tip at the bottom of the diamond. This is never usually on show. 
Depth – This is the diamond's height.
Diameter – The diameter is diamond width. 
Girdle – The girdle is the thin perimeter of the diamond.
Pavilion – This is located between the girdle and the culet; it is the bottom part of the diamond.
Table – The table is found at the top of the diamond; it is the largest facet.

Now you know about the different parts of the diamond, yet it is the crown and the pavilion that are the most important. Their relationship determines the diamond's sparkle. 

When a diamond has been cut well, some of the light enters the diamond and the rest of the light instantly reflects off the crown angles. The light that enters the diamond will then bounce off the walls inside and shoot back to the surface and out of the diamond again. This is what creates the breath-taking sparkle. However, the light will simply escape from the diamond if it has not been cut well.