The Four Characteristics That Determine Diamond
quality (The 4 C's)
Two diamonds may, at first glance, look alike, but the truth
is they are very different. Although they may be of equal size,
each diamond has characteristics unique to itself, so they may
have unique values. To understand these differences is to understand
the 4 C's. Cut, color, clarity and carat-weight. It is the combination
of these four characteristics that determines the value of a diamond.
Let our diamond experts explain the 4 C's to you in more detail
when you visit our store.
Cut Definition In its rough state, a
diamond's beauty is well concealed. Through cutting, the magnificent
optical beauty of a diamond is revealed. A diamond cutter's challenge
is to balance beauty with weight retention from the rough diamond
In the best-case scenario, approximately 50% of the weight is
lost from the original crystal in the cutting process. Because
size is important to many consumers, often cutters sacrifice diamond
beauty in order to save weight, maximizing the size of the finished
Note that cut is also referred to as make.
Many people confuse cut with the shape of a diamond. The shape
you select is a matter of individual taste, and today your choice
is only limited by the skill and imagination of the craftsman.
It is their effort during every stage of the fashioning process
that reflects the maximum amount of light back to the eye. Most
round, brilliant-cut or fancy-shaped diamonds possess 58 carefully
angled flat surfaces, called facets, whose placement will affect
the fire, brilliance and ultimate beauty of your diamond.
The way a diamond reflects and refracts light is dazzling to the
beholder. There are four factors that determine the optical beauty
of a diamond: luster, brilliance, dispersion, and scintillation.
Luster The quantity and quality
of light reflecting from the surfaces of a diamond.
Brilliance The amount of white light
returned to the eye from the diamond.
Dispersion The amount of rainbow colors returned to the eye from
within the diamond.
Scintillation The sparkle, which
is the combination luster, brilliance, and dispersion when there
is movement by the wearer or light source.
How Cut is Graded
In the past diamonds were analyzed, not graded, for cut by visual
estimation. Today, there are several electronic machines used
to determine the angles and proportions relating to the quality
of cut. A diamond's finish, including polish and symmetry, is
graded by human examination through a binocular microscope.
Round Diamonds - The standards for
quality of cutting a round brilliant diamond have been established
by AGS using nearly 100 years of research. AGS Laboratories assign
a numeric cut grade; 0 to 10, 0 being best, complete with all
the proportions and finish parameters for round diamonds. The
AGS numeric cut grade
Fancy Diamonds - Since the proportions
for fancy-shaped diamonds vary the optimal balance of luster,
brilliance, dispersion and scintillation, is different for each
shape. Therefore, no cut grade is assigned for fancy-shapes at
this time. Research is currently underway by the AGS for the future
potential in offering a cut grade for fancy-shaped diamonds.
Cut A diamond cut to optimal proportions, with optimal
polish and symmetry,
with the most weight loss to produce maximum luster, brilliance,
dispersion, and scintillation. Diamonds cut to this standard are
valuable, with only 5% of the round brilliant diamonds on the
cut to this standard.
Diamonds that have very good optical beauty that fall just outside
of the parameters of Ideal Cut diamond. These diamonds are priced
less than Ideal cuts because they are not as rare.
Cut This diamond will appear smaller than it weighs
because it's weight
is retained in the depth. It is cut with a deep pavilion (bottom
of the diamond)
that does not reflect light back through the crown (top of the
Light leaks out the pavilion producing a dark appearingdiamond
beauty. These diamonds are sometimes called nailheads due to their
dark, face-up appearance.
Cut Diamonds that are cut with shallow pavilions
that do not reflect
light back through their crown. The light leaks out from the pavilion,
a washed-out or watery appearance that is not beautiful. Weight
is retained in the diameter, making the diamonds appear larger
weight. These diamonds are sometimes called fisheyes, due to unsightly
reflections in the crown area.
Effect dark area in the center of some fancy-shaped diamonds.
bow-tie in the center of a fancy shaped diamond detracts from
and lowers the value.
Cut in Relation to Value
Cut is the most important factor to a diamond's beauty. Regardless
of the color, clarity, and carat weight, a well-cut diamond will
be beautiful. Cut is so important to the value of
a diamond that it can affect the value by 25% to over 50%.
Fancy-shaped diamonds, since they retain weight from unusual
shaped rough crystals, are often less expensive then comparable
round diamonds. Carat for carat, since fancy-shaped diamonds are
elongated, they appear larger than round diamonds. If a consumer
is interested in maximizing size appearance, they can buy a smaller,
yet larger-appearing fancy shaped diamond of the same quality
for less than a comparable round brilliant diamond.
When shopping for a diamond, ask a professional AGS jeweler about
diamond cut quality. Physically examine diamonds with your own
eyes, shop and compare, and make the best decision for you.
The seven most popular shapes of a diamond.
Definition The amount or presence
of body color in a diamond (colorless to yellowish).
The most prized diamonds are colorless diamonds, because their
beauty depends entirely upon their remarkable optical properties.
In such diamonds, all the colors of the rainbow are reflected
back to your eye. While the majority of gem diamonds appear to
be colorless, others can contain increasing shades of yellow to
brown, some of which are referred to as champagne diamonds. Other
diamonds of exceptional color--red, blue, green, pink, and amber--are
known as "Fancies."
The color grading scale varies from totally colorless to light
color or tinted. The difference between one grade and its neighbor
is very subtle. Experts never try to remember color; they use
master diamonds of known color for comparison.
Very Light Yellow
Definition The presence or absence
of inclusions within the diamond and blemishes on its surfaces.
These slight birthmarks of nature generally do not affect the
beauty of a stone, but they almost always affect its price. Truly
flawless diamonds are extremely rare and very valuable.
Because of their unique optical properties, diamonds, more than
any other gemstone, are capable of producing the maximum amount
of brilliance. While minute crystals of diamond or other minerals
are contained in almost all diamonds, a diamond that is virtually
free of inclusions and surface markings will be judged as flawless.
In these diamonds, nothing interferes with the passage of light
or spoils the beauty. But these diamonds are extremely rare and
will command a high price.
To determine a diamond's clarity grading, it must be examined
under a 10x magnification by a trained, skilled eye. What minute
inclusions there may be make every diamond unique. These are,
in fact, nature's fingerprints and do not mar the diamond's beauty
nor endanger its durability. Without high magnification, you may
never see these inclusions. However, the fewer there are, the
rarer your diamond will be.
* with a comment in the Comments section
of an AGS Report
may be visible to the naked eye
As with all precious stones, the weight--and therefore the size--of
a diamond is expressed in carats.
One carat is divided into 100 "points" so that a diamond
of 25 points is described as a quarter of a carat or 0.25 carats.
Size is the most obvious factor in determining the value of a
diamond, but now you know that two equal sizes can have very unequal
prices depending on their quality. However, remember that diamonds
of high quality can be found in all size ranges. Here are some
other examples that show the approximate size of diamonds of varying