Diamond Cut
First, don't confuse
diamond "cut" with "shape." Shape refers to the general outward
appearance of the diamond, (such as round, emerald, or pear). When a
diamond jeweler (or a diamond certificate) says "cut," that's a
reference to the diamond's reflective qualities, not the shape (or
at least it should be, we have found that even some "jewelers" don't
appear to know the difference between "cut" and "shape").
Diamond cut is perhaps
the most important of the four Cs, so it is important to understand
how this quality affects the properties and values of a diamond. A
good cut gives a diamond its brilliance, which is that brightness
that seems to come from the very heart of a diamond. The angles and
finish of any diamond are what determine its ability to handle
light, which leads to brilliance.
(See Diamond Anatomy for
an explanation of the terms used in the next paragraphs.)
As shown in the images
below, when a diamond is well-cut, light enters through the table
and travels to the pavilion where it reflects from one side to the
other before reflecting back out of the diamond through the table
and to the observer's eye. This light is the brilliance we
mentioned, and it's this flashing, fiery effect that makes diamonds
so mesmerizing.
In a poorly cut diamond,
the light that enters through the table reaches the facets and then
'leaks' out from the sides or bottom of the diamond rather than
reflecting back to the eye. Less light reflected back to the eye
means less brilliance.
Good Proportions are Key
Most gemologists
agree that the best cut diamonds are those that follow a set of
formulae calculated to maximize brilliance. These formulae can be
seen in a diamond's proportions, most importantly how the depth
compares to the diameter, and how the diameter of the table compares
to the diameter of the diamond.
However, the variance in
the proportions between an Ideal
Cut and a Poor
Cut can be
difficult to discern by the casual observer.
Because cut is so
important, several grading methods have been developed to help
consumers determine the cut of a particular diamond. In general,
these grades are:
·
Ideal
·
Premium
·
Very Good
·
Good
·
Fair &
Poor
GWhich Grade of Cut Should I Buy?
Selecting the grade
of cut is really a matter of preference. To make the best selection,
you need to understand the various grades. Please note that the
descriptions below are general guidelines.
Ideal
Cut
This
cut is intended to maximize brilliance, and the typically smaller
table sizes of these diamonds have the added benefit of creating a
great deal of dispersion or 'fire' as well. Ideal quality diamonds
are truly for the person who enjoys knowing that he has one of the
finest things that money can buy. This category applies only to
round diamonds.
Premium
In the case of round
diamonds, many Premium Cut diamonds have cuts that are the equal of
any Ideal Cut diamond, though they often can be purchased at
slightly lower prices than AGS Ideal Cuts. They are intended to
provide maximum brilliance and fire. Like the Ideal Cut, these are
also for the person who enjoys knowing that he has one of the finest
things that money can buy.
Very
Good
These diamonds reflect most of the light that enters them,
creating a good deal of brilliance. With these diamonds, the cutters
have chosen to stray slightly from the preferred diamond proportions
in order to create a larger diamond. The result is that these
diamonds fall slightly outside of some customers' preferences in
terms of, for example, table size or girdle width, though, in many
cases many of the parameters of diamonds in this range will overlap
with certain parameters of diamonds in the Ideal or Premium ranges.
Generally, the price of these diamonds in slightly below that of
Premium cuts.
Good
Diamonds that
reflect much of the light that enters them. Their proportions fall
outside of the preferred range because the cutter has chosen to
create the largest possible diamond from the original rough crystal,
rather than cutting extra weight off to create a smaller Premium
quality diamond. Diamonds in this range offer an excellent
cost-savings to customers who want to stay in a budget without
sacrificing quality or beauty.
Fair
& Poor
A diamond graded as fair or poor reflects only a small
proportion of the light that enters it. Typically these diamonds
have been cut to maximize the carat weight over most other
considerations.
Diamond
Anatomy
Wondering what on earth is the diamond's pavilion? Table? Culet?
The graphic and supporting text below explain the various "parts" of
a diamond.
·
Diameter The
width of the diamond as measured through the girdle.
·
Table This is
the large, flat top facet of a diamond.
·
Crown The
upper portion of a cut gemstone, above the girdle.
·
Girdle The
narrow rim of a diamond that separates the crown from the pavilion.
It is the largest diameter to any part of the stone.
·
Pavilion The
lower portion of the diamond, below the girdle. It is sometimes
referred to as the base.
·
Culet The tiny
facet on the pointed bottom of the pavilion, which is the portion of
a cut gem below the girdle.
·
Depth The
height of a gemstone, from the culet to the table.
·
Read
more about the Four Cs of
diamonds... |