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.
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.
It's easy to see that the
deep-cut diamond shown above will have a higher carat weight,
but is clearly the less desirable stone! Many
jewelers will not discuss cut proportions unless the customer
specifically asks; a stone rich in carat weight
but poorly proportioned can be deeply "discounted,"
giving the buyer a false impression of a great deal.
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.
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
Fair & Poor
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
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.
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.
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.
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.
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.
Most of these type of cut diamonds can be found in retail
mall jewellery stores.