Nothing flaunts the splendour of a diamond like its cut. Top to bottom a diamond is comprised of a crown, girdle, and pavilion. If the pavilion angle is cut too deep, the stone will look dark. If it is too shallow, a diamond will look watery.
Well-cut diamonds will exhibit a breathtaking performance of light.
Many diamond experts are convinced that the optimal brilliance of a diamond is determined by one specific set of proportions. But cutting a diamond to ideal proportions has a cost. In some cases half of the crystal's weight is sacrificed. Consequently the diamond is sold at a relatively higher per-carat price.
The standard round-cut is by far the most popular cut. It has 57- 58 small, flat, polished surfaces called facets which account for the breathtaking sparkle.
Up to 60% of a diamond's cost is based on the cut.
(Proportions table of a Round Brilliant)
Table %
Crown Angle °
Crown Height %
Pavilion Depth
Girdle Thickness
Total Depth
Polish/Symmetry
53 - 58%
34 - 34.7
14 - 16.3%
42.8 - 43.2%
Thin to Medium
(1.0 % to 3.0%) Medium to
Slightly Thick
( 1.7% - 4.5%)
58 - 62.3%
Excellent - VG
52 - 60%
33 - 35.1
13.5 - 16.8%
42.5 - 43.5%
Very Thin to Slightly Thick (0.4% to 4.5%) Thin to Slightly Thick (1.0% to 4.5%)
58.3 - 62.99%
Excellent - VG
51.5 - 63%
31.1 - 35.8
11.6 - 17.9%
42 - 44%
Very Thin To Slightly Thick (0.4% - 4.5%)
<58.3% - >63%
Excellent - Good
51 - 64%
31.6 - 36.4
11.1 - 18.1%
41.5 - 44.9%
Very Thin To
Thick (0.4% to 5.5%)
<58.3% - >63%
Good - Fair