The Round Brilliant cut is the most common of all the diamond shapes. Originally introduced to the industry around 1900, the Round Brilliant cut maximizes light return from the crystal in the forms of Brilliance, Fire and Scintillation.

Comprised of 58 facets, the Ideal cut Round Brilliant has no peers in terms of creating dispersion what we term Fire while maintaining a perfect balence with the return of pure white light through the Table.

Ideal cut Round Brilliant diamonds with perfect internal symmetry will also exhibit the H&A Hearts and Arrows effect when observed through an H&A viewer.

CUT CLASSES

Class1A

Class1B

Class 2A

Class 2B

American Ideal Cut

International fine trade cut

Table %

53-58%

52-60%

51.5-63%

51-64%

Crown angle°

34.0-34.7

33-35.1

32.1-35.8

31.6-36.4

 Crown height %

14-16.3%

13.5-16.8%

11.6-17.9%

11.1-18.1%

Pavilion Depth %

42.8-43.2%

42.5-43.5%

42-44%

41.5-44.9%

Girdle Thickness:
Word descriptions

Thin to Medium (1.0% to 3.0%)
Medium to Slightly thick (1.7% to 4.5%)

Very thin to Slightly thick (0.4% to 4.5%)
Thin to Slightly thick (1.0% to 4.5%)

Very thin to Slightly thick (0.4% to 4.5%)

Very thin to Thick (0.4% to 5.5%)

Total depth %

Determined by
factors already
considered above

58-62.3%

58.3-62.99%

<58.3%
>63%

Polish/Symmetry

NOT A PRIMARY
DETERMINING
FACTOR

Excellent -Very Good

Excellent toGood