The
pavilion angle is a very important
element of a diamonds proportions
and it is greatly responsible for
the amount of brilliance that a diamond
will display.
Diamonds
which have ideal to very fine
cut with proper pavilion angles
provide the greatest brilliance.
The facets on the bottom of a
diamond are called pavilion facets.
When you look at a round brilliant
cut diamond face-up, the pavilion
facets act as mirrors which reflect
the image of the table, the large
facet on the top of the diamond.
This white table reflection seen
within the center of the diamond
provides the sparkle in the center
of the diamond. |
Depth
% |
59%
- 63% |
59%
- 63% |
Table
% |
52.4%
- 57.5% |
51.4%
- 62% |
Girdle
Thickness |
Thin
to Medium |
Very
Thin - Thick |
Cullet
Size |
None
- Medium |
None
- Medium |
Polsih |
Excellent |
Excellent
to Good |
Symmetry |
Excellent |
Excellent
to Good |
Flourescence |
None
to Faint |
None
to Faint |
Length
to Width Ratio |
1 to
1 |
1 to
1 |
Crown
Angle |
33.7%
- 35.8 Degrees |
32.2
- 36.8 Degrees |
Crown
Height |
15%
- 16.2% |
13.1%
- 16.2% |
Pavilion
Angel |
40.5
- 41 Degrees |
39.7
- 41.7 Degrees |
Pavilion
Depth % |
42.2%
- 43.8% |
41.7%
- 44.8% |
|
In a very fine to Ideal cut diamond
the diamond will exhibit a white table
reflection that appears in the center
of the table. This reflection
should be 1/4 to 1/2 the size of the
large table facet on top of the diamond
The
AGS Ideal 0 Cut grade includes a narrow
range of pavilion angles from 40.5
degrees to 41 degrees.
Ideal
to Very Fine Cut Diamonds have pavilion
angles between 39.7 Degrees and 41.7
Degrees. Diamonds within this range
usually provide excellent brilliance.
Diamonds that have depths outside
these ranges usually cost less, but
a degree of brilliance is lost. The
diagram below illustrates how the
white table reflection changes in
size as the depth percentage changes |