The 'cut' of a diamond does not refer to its shape, as most people believe. When
laypersons talk of a 'Princess' cut or a 'Round" cut diamond they are referring
to the shape of the diamond. However, in technical terms the cut of the diamond
refers to the talent with which a diamond cutter has managed to add facets to the
diamond to achieve maximum carat size and brilliance
The beauty of diamonds lies in the millions of flashing sparkles that are reflected
as soon as light hits the diamond. This beauty can be reduced or enhanced by the
cut of the diamond. There is no single measurement or aspect that determines how
good the cut of diamond is. Instead it is a collection of dimensions that determine
how well the diamond will perform.
Understanding width and Depth
It is primarily the width and the depth of a diamond that determines how much light
enters the diamond and in which direction it is reflected back. An ideal cut diamond
is one that is cut in a manner so as to allow maximum light to enter the diamond
and then be dispersed back from the top of the diamond.
Shallow cut diamonds:
also referred to as 'fisheye' diamonds these are cut too shallow. There is not enough
depth in the diamond to reflect the light back from the top facet and the light
leaks out from the bottom of the diamond. Many cutters take this route to retain
the maximum carat weight from the original diamond rough. It is also a way to make
the diamond appear 'larger'.
Deep cut diamonds:
Also referred to as 'nail head' diamonds, these are too tall or deep resulting in
light leaking out from the sides of the diamond. Nail head diamonds generally feature
a dark center resulting in lower brilliance.
Understanding Other Proportions of a Diamond
It is also important to understand that while the width and the depth of a diamond
do largely determine its cut quality, These are not the only factors. Here are some
of the other important dimensions.
Diameter: The width of the diamond as measured through the girdle.
Table: This is the largest side or facet of the diamond - in almost all cases
the top, flat side.
Crown: The top half of the diamond. Typically measured from the table to
Girdle: This is the narrow rim where the crown and the pavilion meet. it
is generally the largest diameter of the stone.
Pavilion: this is the lower half body of the diamond. Typically measured
from the girdle to the culet. it is also known as the base.
Culet: This is the tiny bottom facet at the base or point of the diamond.
Ideally a culet should be so small as to be invisible to the naked eye.
Depth: The total height of the diamond as measured from the culet to the
Understanding Polish & Symmetry
Two Lesser-known aspects that also affect the brilliance of a diamond are the polish
Polish: this refers to the smoothness with which the sides or facets of the diamond
have been polished diamonds have decreased sparkle and can look dull.
Symmetry: this refers to the way the various facets have been aligned. If face lets
are not aligned properly it can result in the light being misdirected and a reduction
in the brilliance of the diamond.
Other than the diamond cut, the other Cs that affects diamond quality should also
be considered: Diamond Carat Weight, Color and clarity.