Diamond Education Cut grading classification across diamond shapes

Round Brilliant Cut

Crown and Pavilion Segmented

The round brilliant is the most brilliant of all diamond cuts. Brilliant cuts were first developed by Marcel Tolkowsky (1899–1991) who came from a Belgian family of diamond cutters, and derived the cut from mathematical calculations that maximised the brilliance and dispersion of light.

Since its creation in the early twentieth century, the round brilliant cut has become the most researched and popular of all cuts. It is comprised of 58 facets and naturally follows the crystal shape of a rough diamond therefore designed to give maximum scintillation, beauty and fire. The cimplest cut is a single cut, a form of cutting a round diamond with only 18 facets. In the 1980s in Japan, it was discovered that a round brilliant diamond with exceptional symmetry, when viewed through a special viewer displayed a pattern of hearts and arrowheads. To read more about the Hearts and Arrows effect please click here.

Based on our experience, grading classifications from most grading laboratories translate roughly to the table below:

ROUND CUT Excellent Very Good Good Fair Poor
Depth % 60 to 63 58 to 64 57 to 65 56 to 67 >56 or <67
Table % 53 to 58 52 to 62 51 to 65 50 to 67 >56 or <67
Symmetry Very Good to Excellent Good to Excellent Good to Excellent Fair to Excellent Poor to Excellent
Polish Very Good to Excellent Good to Excellent Good to Excellent Fair to Excellent Poor to Excellent

To read more about the round brilliant cut shape, please click here.

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