“Diamonds are the most precious objects many people ever see.”
have developed precise standards for grading diamonds that determine
their value. Learning these standards of diamond evaluation
in this diamond guide will help make your buying process complete
and comfortable. A diamond’s value is influenced by its rarity
and the expert opinion of diamond graders. At ForeverJewelers.com
we are determined to teach you the significance of the 4
Cs used by diamond graders. Our diamond guide will help
you make an educated decision with your diamond
One carat equals 0.2
When weighing diamonds
the measurement used is called a carat (1.00). Each carat is
equal to 100 “points”, like pennies to the U.S. dollar. Twenty-five
hundredths of a carat or 0.25ct is often referred to as a "quarter
carat" or "25-points". The same goes for five
tenths of a carat or 0.50ct, one might call it “half of a carat”
or "50-points", and so on. In order to determine the
exact weight of a diamond or any other gemstone, it must be
When a piece of jewelry
has many of the same type of gemstones in it, the carat weight
is determined by weighing all of the same stones together. The
sum of these stones is then referred to as
“carat total weight”.
In general, the larger
the carat weight, the more it will cost. This is because larger
stones are more rare.
1.00ct = 100
five diamonds, each weighing 0.20ct
will equal 1.00ct
t.w. or ctw
Most people think that
all diamonds are colorless because the majority that are sold
range from nearly colorless to a slight yellow or brown hue.
Diamonds occur in every range of color. Very few are truly colorless.
Institute of America has developed a color grading scale,
starting with the letter D, that uses letters of the alphabet
to distinguish the various colors in diamonds without confusion.
D E F
G H I J
K L M N O
P Q R S T U
V W X Y
The amount of color you
see depends largely on a diamond’s size, how it is cut and how
it is mounted. The larger a stone is, the more apparent its color
will be. An analogy of this is comparing a glass of red wine to
a carafe of red wine. The glass of wine will appear lighter in
color than the whole carafe.
Clarity is the degree
to which a diamond is free of inclusion or blemishes. An inclusion
is an internal clarity characteristic such as other mineral crystals,
feathers, breaks or drill holes created by clarity enhancement.
A blemish is a characteristic
found on the outside of a diamond’s surface. Small nicks, scratches
or rough parts left on a finished stone are considered blemishes.
In order to make clarity
grading easier to learn and understand, G.I.A.
created a universal method of grading diamonds. Starting with
flawless, which is very rare and has no inclusions or blemishes
that can be detected by an expert diamond grader under high
magnification, and ending with imperfect, the exact opposite,
the middle range is where the majority of diamonds are found.
As with weight and color,
the effect of clarity on value relates directly to rarity. Flawless
or nearly flawless diamonds are more rare and therefore demand
much higher prices than diamonds with slightly or very noticeable
clarity characteristics. Location of inclusions and blemishes
also has a bearing on the final clarity grade. Inclusions in
the center of a diamond's table may negatively affect the overall
clarity grade more so than if the inclusion is found in the
crown facets. Diamonds in the SI clarity range are often called
"eye-clean" diamonds in the trade when they are such
that the inclusions are present, yet difficult to see without
magnification. These should not be overlooked as they will often
be more affordable and may allow for the purchase of a better
grade of color, cut or larger carat size.
F – (Flawless)
A diamond with no internal inclusion or external blemishes
found using 10x or higher magnification.
I.F. – (Internally flawless)
A diamond with no inclusions found using 10x or higher magnification.
Minor blemishes on the surface may be tolerated.
– (very, very slightly included to the first degree)
A diamond that contains very minute inclusions that are very
difficult to see for a skilled diamond grader with10x magnification.
(very, very slightly included to the second degree)
A diamond that contains very, very small inclusions that
are difficult to see for a skilled diamond grader with10x
(very slightly included to the first degree)
A diamond that contains very small inclusions that are only
visible with difficulty under 10x magnification to a trained
(very slightly included to the second degree)
A diamond that contains very small inclusions that are only
visible with 10x magnification to a trained eye.
– (slightly included to the first degree)
A diamond that contains small inclusions that can be seen
under 10x magnification and may be noticeable when guided
with the unaided eye.
(slightly included to the second degree)
A diamond that contains noticeable inclusions that can easily
be seen with 10x magnification and can often be easily seen
when guided with the unaided eye.
(slightly included to the third degree)
A diamond with inclusions noticeable without magnification.
This grade is not recognized by G.I.A.
I3 – (imperfect to the first,
second and third degree)
A diamond with obvious clarity defects that may have large
cleavage or inclusions that may influence durability. These
stones also often lack transparency and brilliance.
These are diamonds
that have been physically altered to make them appear more
desirable. They can also make the cost of buying a diamond
more affordable, especially with large stones. There are ways
of making some inclusions less noticeable in larger, more
included diamonds. Fracture-filling
is a process in which a glass-like substance is melted and
injected under extreme pressure into nearly colorless diamonds
to create a better-looking clarity. By filling the inclusion,
light is able to pass through it and it is therefore less
noticeable. Sometimes diamonds can be drilled with a laser
allowing dark, unsightly inclusions to be "bleached"
and create less obvious characteristics.
These effects are
safe and durable providing that your professional jeweler
is made aware that your diamond has been clarity enhanced.
Exposure to direct fire or strong acids or bases could reverse
the clarity enhancement process. If repairs or adjustments
need to be made, ForeverJewelers.com is fully capable and
willing to work on your clarity enhanced diamonds.
Cut is the human contribution to a diamond’s beauty. The cut can enhance color
and hide inclusions if done correctly. In terms of the 4 Cs,
cut includes a diamonds style and make. Style
is the basic pattern of the facet arrangement, the shape of
the stone, or both. Make refers
to proportions and finish.
Common diamond shapes
have three basic facet arrangements: brilliant, step or mixed.
- Brilliants have
facet patterns that radiate from the center of the stone towards
the edge in triangle or kite-shaped facets. (round brilliants)
- Step cuts have
concentric rows of facets parallel to the girdle. (emerald
- Mixed cuts have
a combination of brilliant and step facets. (radiant cut)
of cutting will create an attractive appearance, but proportions
are the key. When a diamond’s proportions are correct, it will
display a brilliant, fire-like effect. Many modern cut diamonds
have near-perfect or perfect proportions. When buying antique
diamonds, the proportions can be different and sometimes not
in proportion. This, however, creates a unique display of of
its own and is often desirable.
are comfortable with the terms used in this diamond guide, you
will be ready to make an educated purchase. Browse our collection
rings and other fine diamond jewelry. If you have any questions
concerning grading and buying diamonds,
gemstone jewelry, or about our web site, do not hesitate
to call or
e-mail ForeverJewelers.com. A well-educated diamond professional
will be able to answer all of your questions.